Check Brake Fluid

Many people overlook checking the brake fluid in their car, then wonder why brake system repairs are so expensive. Checking the brake fluid only takes a couple seconds and can save you thousands of dollars in repair bills. First, let's get as few things straight. Brake fluid does not 'wear out'. Some kinds of brake fluid become contaminated with moisture, and if your brake fluid is dark then it is most likely time to change it. Brake fluid should always look exactly as it did when it was poured out of the bottle. There are several types of brake fluids, and not all of them absorb moisture. The brake fluids that do not absorb moisture (DOT4, and DOT5), are permanent, meaning they never need to be changed or maintained, unless there is a leak.

Now we get to how to check the brake fluid. The master cylinder is at the end of the brake pedal, in almost all vehicles. So your first job is to locate it. On most cars, it is under the hood on the driver's side against the firewall. There is a black cap on it that specifies to use only a certain type of brake fluid in the reservoir. Do not get the brake fluid reservoir confused with the hydraulic clutch fluid reservoir on vehicles with standard transmissions. Sometimes they both get fluid from the same reservoir, but not always, so make sure that you have the right one. Then you can remove the cover from the brake fluid reservoir, and check the level. The brake fluid level should be about 3/8 of an inch from the top of the reservoir, and there is usually a set of marks to go by in the side of the brake fluid reservoir to make things easier. If the fluid is low, then it might be an indication of needing some new brakes, or an indication of a brake system leak, if the (BRAKE!) warning light is on. If there is a float in the master cylinder reservoir, then there will also be a low brake fluid warning system in your car. If the fluid is full, and this light is on, then the float is either stuck or bad (both are common problems). Make sure that you are not dealing with a leak, or a need for new brake linings before adding any fluid to the system, because they are specifically designed to only hold so much fluid.

Now that you know about how to check the level of the fluid, we will look into the dark color or muddy looking brake fluid that only happens on DOT3 brake fluids. The dark color is water that the brake fluid has absorbed. This is a normal part of how it works, but should be monitored. At the auto parts store, there are brake fluid test strips, or litmus strips. These can be dipped into the fluid so you can check the quality of the fluid. Remember, this applies to DOT3 brake fluid only. Less cars are coming equipped with DOT3 brake fluid every year, and the problem will soon take care of itself. DOT4 and DOT5 brake fluids actually repel moisture, and that makes hydraulic brake system parts (the expensive ones) last longer. You can replace a higher number brake fluid where it calls for a lower number. This means DOT4 and DOT5 are acceptable in DOT3 systems. However you can not replace a lower number fluid when it calls for a higher number fluid. So, that means that DOT3 fluid can not go in a DOT4 system. You should never mix brake fluids, either. If you make the conversion to a newer fluid, make sure to only use that kind of fluid from that point forward.

That's it! you now know everything you need to know about how to check the brake fluid in your car.

Rear Axle Oil

Changing the rear axle oil on any vehicle is fairly straightforward. If you need to know how to do it, here are some 'general instructions' off the top of my head. I did some time at a 'quick change and lube' shop, so I can tell you from quite a many hours of experience of doing one after another, after another on this. Do not put oil in a rear end that leaks axle oil. You will want to inspect it very carefully, and hope you are changing this oil only as a maintenance factor. Axle oil leaks can get very expensive

Jack the rear end up, and support it securely on both sides. I was in a pit (under ground) and the cars rolled over the top of it, that is the only difference, besides the methods we used to fill the system which you will find out about shortly. So you have the rear end up and supported on both sides, now look at the center of it. Some call it the pumpkin, on the rear end. If there is not a drain hole in the bottom of it, then you will need to get the rear cover off it. The gasket is only silicone, and everybody has silicone. Black RTV is the best for this application, if you have the extra money for it. Anyways, there is oil in there, and you will need to catch it. So, put your drain pan under the pumpkin, and either pull the drain plug, or remove the cover plate.

Once you get it drained out you may want to clean it up a little bit with some cleaners if you have the whole cover off it. Make sure everything is clean and the draining has stopped, and replace the drain plug.You are now, done draining it!

Leave the drain pan in place, and look on the middle of the pumpkin on the driveshaft side on the top half of the assembly, and you will see a small plug that you can fit a ratchet into. You may need an extension to reach it. Anyways, get it out of there, it is the fill plug for the differential. You will now open your axle oil and pour in into the fill plug, until it comes back out. When it does not take any more, then it is full, ad you replace the fill plug.

Getting the oil into the fill plug can sometimes be more difficult than it sounds, though. If the fill plug for your differential is in a tight spot, you will not have enough room to even get the bottle of oil in close to it. You can use a hose on the end of your bottle or make a pump to get it up there. Ours were controlled by pressure from air, and it shot out into the fill hole for us when we hit a button. Anyways, hand pumps work nice in tight situations. I keep one in my tool box, and I use it more than anything else in there, almost!

Keep your rear axle in good shape, and it will keep you happy for a long time. If you do a lot of fast acceleration, then you will want to change your rear axle oil a bit more often that recommended by the manufacturer. Always consult your service manual for specific things, like fluid type and capacity. This is only meant to be general instructions so you get the idea, of how it is done. The main thing is to stay safe, you don't want the pumpkin on your rear end to smash the pumpkin on your shoulders.

Locations: Oxygen Sensor

When trying to find the location of an oxygen sensor on your car, you should know that there is more than just one of them. Each side of your engine has two oxygen sensors, located somewhere along the exhaust system, depending on their names. They are called sensor 1 and sensor 2. This does not mean that there are always 4 oxygen sensors on a car, as there can be anywhere from one to four of these. That is why it is most important to know which sensor you are trying to locate before going in to change it.

Bank 1 or Bank 2

Each side of your engine, or row of cylinders, is considered a bank. A four cylinder only has one row of cylinders, so all sensors on that engine would be bank 1 sensors. If your engine is a V-6 or V-8 then you will also have separate banks. Bank 1 is the side of your engine that has the #1 cylinder. On GM and Chrysler products, the Bank 1 side is towards the front of front wheel drive cars, or on the driver’s side of rear wheel drives. Ford “V” style engine blocks are the opposite, and have the first cylinder on the passenger side on rear wheel drive vehicles, and firewall side on front wheel drive ones. If you are still confused, a quick check of which side of your engine contains the number one cylinder can be found by simply searching for a firing order diagram for your car.

Sensor 1 or Sensor 2

Each cylinder bank gets information from 2 oxygen sensors. This is why the names of sensor 1 and sensor 2 also have to be specified when trying to locate the oxygen sensor. Modern cars with four cylinder engines have 2 oxygen sensors. One of them (sensor one, or “S1”) will either be located in the exhaust manifold or in the exhaust pipe, just below the manifold but still very close to the engine. The job of sensor 1 is to monitor the efficiency of the engine. Sensor 2 is farther to the back of the car, either located in the catalytic converter, or in the exhaust pipe just behind it. There is a Sensor 2 (or “S2”), for each catalytic converter. The job of sensor 2 is to monitor the efficiency of the catalytic converter. So it can be a safe to assume that if you are having problems with sensor 2, then there might be a problem with the catalytic converter. The main problems that come up with Sensor 1 usually involve the heater circuit, which only lasts about 100,000 miles.

Tips and Tricks for Oxygen Sensors in your car.

The exhaust manifold is bolted to the side of the engine and has a big pipe running under the car bolted to it. You can usually reach these sensors from the top of the engine, but if you have to go through the bottom, be prepared to remove a protective cover under there, in order to get to the sensor. Getting the sensor off is usually fairly easy with the correct oxygen sensor tool which looks like a socket with a big groove cut out of it, or a 13/16 wrench which will not spread and slip on the sensor (if you use the boxed end). The socket design actually has a tendency to spread which ruins the tool and only makes the sensor harder to remove when you finally give up and put a wrench on it. Also, since sensor 1 is always the closest one to the engine be prepared to have to use some lube on it to get it out. It is not uncommon to have to turn a little then spray wd-40 on it, just so you can turn it a little more. When putting it back in, be sure to use some of the copper based anti-seize compound on the threads, so it is not as difficult to remove next year.

Now you know how to locate the oxygen sensor on any car, and can tell the difference between B1S2 or B2S1 in the descriptions. You should be able to get to the right sensor without any problems. If you need to know how to test it, then you can read this article about how to test an oxygen sensor. Stay safe, and good luck!

Horn Fixes

Horn problems come in many different flavors. They either don't work, are on all of the time, or only work when they 'want to'. Since it is not very cost effective for my customers to just start changing everything on the system and crossing their fingers to hope it works, there is some actual diagnosis that needs to be done. That is what I am here to explain to you how to do. If you want someone to tell you to just start changing things until it is fixed, then go read another article. Fair?

Okay, I see you are interested in getting things fixed right, the first time since you are still reading. So let's get down to the different types of problems and the diagnostic procedures that are associated with them. Before working on anything, the first thing to do is check the computer for codes. Many of today's cars have a body control module (B.C.M.) which play a big part in controlling the horn. So, you need to make sure that there are no trouble codes set. Not all trouble codes will turn on a warning light, so be sure to check them with the proper scan tool that can read codes from the body control module(not all of them can), if your vehicle has one. You also need to make sure that the different modules in the vehicle can communicate with each other. If there is a problem with communication, your scan tool will alert you. If you find any problems with those things, they need to be corrected before going any farther. If everything is 'all good there', then proceed with the inspection of the system.

To begin inspecting the horn system, here are the things you need to check:

* The fuse - If the fuse is blown, then there is a short in the system, and it needs to be found, or it will keep blowing.
* Check for improperly installed aftermarket accessories, such as radios or amplifiers and such, that might be spliced into the wrong circuits.
* Check for obvious damage to the related wiring, connections, and components that work the horn system.
* Check for corrosion or other debris at the point where the horn bracket is mounted to the vehicle. It can get in there and cause a 'bad ground'.
* Check the torque of the bolt holding the horn bracket to the vehicle. If it is loose, it can actually damage the horn, from a low voltage condition.

If all of the basic stuff passed the inspection, then we move on to the 'problem specific' diagnosis. We will work with a horn that does not work in this article. Other problems will be covered in other horn related articles. Anyways, you will need a test light, and probably the repair manual for your vehicle to go much farther.

Okay, so you got your test light and repair manual. Let's get started with this basic run down on diagnosing a horn that does not work.

1. With the key off, remove the horn relay and check for power from the relay coil wire and an external ground source. If there is power there, move on to step 2. If not, then repair the wiring problem between the battery positive terminal and the horn relay positive terminal, and the horn will work.

2. Put the test light between the relay positive coil terminal, and on the relay control circuit (one that goes to the button), and press the horn. If it has power move to step 3. If not, then do you remember that clock spring I told you about? Well, there could still be a problem with the button, if there is no air bags in the vehicle. Look in there, and you will see the problem. If it has air bags, then the steering wheel needs to come off. If not then you can change the button, with a cheap kit from the auto parts store.

3. At the horn switch, check power between positive terminal and a good ground source. If there is no power, then there is a problem in the horn switch itself. If there is power there move to step 4.

4. Get a wire with a 15AMP fuse in it, and run it between the battery and the output terminal of the relay socket for about 1 second. If the horn operates, change the relay. If not, then put the relay back in the socket move to step 5.

5. At the horn disconnect it, and put the test light between the power wire to the horn and a good ground source, and press the horn. If there is no power there, then there is a bad wire between there and the horn control terminal on the relay. If there is power, move on to step 6

6. Hook the test light between the power and ground terminals on the horn (if it has 2 terminals), and press the horn. If there is power there, then replace the horn. If there is no power there, then there is a power int he horn ground circuit. Remember the B.C.M.? That would be a possibility, here.

If you follow these instructions, you should be able to get most any horn back in working order, if it is dead when you try to use it. Oh, yeah I forgot to mention, if you need some discounts on auto parts, as a thanks for reading, type of thing. To see the latest promotions from Advance Auto Parts, look at my profile page. They usually have a 20% off total purchase sale happening, if you know what you need and can buy it online then pick it up at the store. I am always happy to help, as I know how it is to need it and not have anybody to turn to.

I hope this article and my resources have been helpful to you. Have a good day and thanks for reading! 

Vacuum Gauge Use

As the piston in your engine pulls down, it draws air into the cylinder. This creates a vacuum in the intake manifold, and monitoring this pressure can give you a good look into the health of your engine. That is done with a vacuum gauge. It is a must have for any mechanic's tool box, and anybody who tells you different does not have a clue what they are talking about. A vacuum gauge is nothing but a gauge with a piece of vacuum hose on it, that is used to measure the amount of pressure in the intake manifold of your engine. This is very important to monitor when diagnosing an engine, because you need to know how the air is moving through the engine as it runs, in order to diagnose many different problems. The only thing you need to know about hooking a vacuum gauge to the engine is to make sure that everything is hooked up. This means you will have to tie it in to the lines that are there. If you 'bypass' one of the systems that run off the vacuum hose you are tied into, then that can affect the readings of the gauge and ultimately lead to a false diagnosis (e.g. waste of time and money).

There is no mystery to how to read a vacuum gauge, and they even come with excellent instructions. But if you have one in your toolbox, and just do not know how to read it, then this article will prove to be an invaluable resource to you. So now you have the vacuum gauge hooked to the engine, but what do you do now, right? Well, about all you can do is watch the needle, and play with the throttle. Depending on what the needle does and how it reacts, you can determine what is wrong with the engine. There are 15 different ways the vacuum gauge can read, and here is a list of them, and what they mean.

1. A normal engine will have a vacuum reading of 20in/hg at sea level, and that number will drop 1 in/hg per every 1,000 feet of elevation above sea level. The needle will be steady and not moving at all on an idling normal engine with good compression, no vacuum leaks, and no ignition system issues.

2. When you open the throttle to make the engine accelerate quickly, the needle should drop down close to 0, very quickly. Quicker is better. Then as you close the throttle the needle should go up past the normal 20 in/hg to something like 25-30, then return back to normal after about 1/2 a second.

3. Racing engines with big camshafts will have lower levels of vacuum, and the needle will shake while idling about 1 in/hg. This is from the valve overlap on the big race car camshafts causing turbulence in the intake manifold at idle, since they are designed to run at high RPM, instead of for maximum fuel economy.

4. A normal engine with worn rings, or in bad need of an oil change will have the same 'lower than normal' reading like the race car engine, but the needle will still remain steady while the engine is idling. Then when you rev it up, the needle will drop all the way to 0. Then when you let go of the throttle to let it close, the needle will rise up to only about 23in/hg instead of the 25-30 of a normal engine. This is because the rings are not sealing good enough to pull the proper amount of air into the engine. At this point, you would change the oil, and try again.

5. If the needle has the right amount of vacuum while the engine is idling, but fluctuates 1-2 in/hg down, then the problem is a sticky valve. Valve jobs are not cheap, either.

6. A bigger fluctuation than the plain sticky valve issue would be a downward fluctuation of about 6-8 in/hg. If you see a big fluctuation like this, then the engine has a burned valve that is leaking the whole time the engine is running. To find this valve, you would do a compression test of each cylinder, and remove the head to change the burned valve.

7. A slow fluctuation of 2-4 in/hg means that there are some valve seating problems, and the best way to fix that issue is (once again) a valve job.

8. A needle that fluctuates 4-6 in/hg while idling, and gets bigger as you accelerate it, is an indication of worn valve guides. If this is the case, you would look for which spark plug was fouled, and either do the valve job, or 'try' replacing the valve seals to try to buy some time before the next valve job.

9. If the needle holds steady while idling, but fluctuates wildly (10 -14 in/hg) while accelerating, then that means that the valve springs are worn. They are much easier to replace than a valve, and usually do not involve removing the cylinder head to change.

10. A low and steady reading on the gauge indicates a problem with late valve timing, or a vacuum leak. You can spray flammable fluid like carburetor cleaner along your vacuum hoses and gasket mating surfaces to see if the engine revs up, in order to find a vacuum leak very quickly. If there are no vacuum leaks on the engine then it means it is time to do something about the timing belt before it breaks!

11. A steady reading at 15 in/hg usually means late ignition timing. Just advance the distributor until it comes up to normal. If the needle also pulses, then check the gap on the spark plugs as at least one of them will be worn or too big, causing a pulsing fluctuation.

12. A low reading of 3-6 in/hg while the engine is idling is an indication of a major vacuum leak. This will usually be something like a throttle body or carburetor gasket. Look and listen for big vacuum leaks in the engine, they will be fairly obvious to hear while the engine is running, once you are aware that there is a problem in the system somewhere. Other than that, you will have to go through the whole vacuum system and make sure all the hoses are hooked up properly.

13. A needle that starts out normal, but drops as the engine runs more and more is a sign of a bad head gasket. Though vacuum gauges are not usually used to diagnose a head gasket type of issue, if this happens you can rest assured that there is definitely a blown head gasket in the engine.

14. If the reading on the needle starts out normal, but decreases to 0 as the engine runs and before dying, that is an indication of a clogged exhaust system. This can be verified by loosening the exhaust from the engine and runningn it and making sure that there are no other problems on the vacuum gauge.

15. If you have a carbureted engine and the needle fluctuates between 13-17 in/hg, then you need to adjust the air/fuel mixture screws for the idle circuit. Once you get it right, then the vacuum levels will get steady and level out to normal.

I hope this helps you figure out what is wrong with your engine as quickly and efficiently as possible. You have learned from a pro, so now you know there are no magic tricks or anything like that involved with using a vacuum gauge. If you do not have one, you should get one, as they only cost about twenty dollars, and can save you a ton of money versus taking it to a shop for a diagnosis that may or may not be correct. I mean, does the mechanic at the shop you work at know how to use a vacuum gauge, and what all those needle reactions mean? If not, then point them in this direction.

Thanks for reading. 

Why Engine Won't Start

It takes 3 basic ingredients to make an engine run, and if you have an engine that will not start, then it is missing at least 1 of those 3 things. The 3 basic necessities are spark, fuel, and compression. There are quite a few different individual things that will cause a car to crank but not start. For this reason, you need to find out which system or set of systems is missing up. In other words, which of these three basic things are missing. You need to look into the engine for these things. Often this is not possible to do without special tools, but if your engine has spark plug wires, you can easily pull one loose to check for spark, which will be explained.

When the engine does not start, the first thing you need to do is check the fuel system for proper operation. This is easily done by spraying some starting fluid, gas, or other flammable liquid in the engine. You can either open the throttle and spray it in there, or spray it in a vacuum hose that is connected directly to the intake runners that et air into the engine. If the engine starts, then the problem is in the fuel system, and a bad fuel pump is a likely cause, so you would look into if the fuel pump is coming on, and building up the right amount of pressure, etc...

If the engine does not start when you spray the flammable liquid in it, then the problem is not likely to be in the fuel system and is probably going to be in the ignition system. To check for spark is easy on most engines, just pull a spark plug wire loose, and stick an old spark plug in it, while holding the spark plug to the engine block. Be sure to wear a glove so you don't get shocked, and have someone try to start the engine. If the spark plug does not spark, then there is a problem in the ignition system. If it does spark, then there is either going to be a problem with the firing order, or compression in the engine.

If the spark plug is getting spark or not, you need to check for compression in the cylinders. This is easy by pulling out a spark plug, and sticking your finger in the hole, and have someone try to crank the engine. The cylinder should build up enough pressure to push your finger off the hole. There is usually close to 150 PSI built up in engine cylinders on your car. If there is not any compression building up in the cylinders then you will want to make sure the camshaft(s) turn(s). If the camshaft does not turn then there is a possibility that valves could be bent in the engine, causing you to remove the head to fix them. If this happens it will be because the timing belt has broken.

Now you know what to look for, so you can find which systems are messing up in order to get your engine cranked up again. If you need to know specific information about your vehicle, be sure to see the repair manual, which you can usually find online for free.

Water in the Oil

When you check the oil in your engine and it looks like someone poured a chocolate milkshake in your engine, then it is safe to say that there is water in the engine oil. When most people see water in the engine oil, they immediately think about a blown head gasket. Although it is true that when a head gasket leaks, it can cause water to mix with the engine oil, it is not always the cause. Depending on the design of the engine water being mixed with the oil can be caused by something as simple as a leaking intake manifold gasket.

If the engine in your vehicle is a “V” style engine with the intake manifolds that seal to the block, you should be aware that the oil gallery is directly underneath the intake manifold. You should also be aware that coolant circulates through the front and rear ports on the intake manifold, to provide cooling to the cylinder heads. Of course, there is a gasket between the cylinder head, and the intake manifold. Some ports hold vacuum to supply air to the cylinders, and some are under pressure because they are part of the engine’s cooling system. There are also seals between the intake manifold and the block, but they are not important for this situation.

Anyways, in the name of being environmentally friendly there was a new type of antifreeze developed that was safe for animals to lick up without being poisoned. This is because the new coolant is made out of food byproducts. Not bad, huh? Very bad idea though. Food has bacteria in it, and the bacteria eat everything it comes into contact with. These bacteria eat through the weakest point first, and that is the intake manifold water jacket gasket. Once that happens, you have hot pressurized water spraying the inside of your engine. Sure there are tablets you can add to your cooling system with this kind of antifreeze that will protect the surfaces on the inside of your engine’s cooling system from the bacteria, but they are not generally available to the public, and they are not something that everybody knows about. The auto manufacturers sure pulled a smooth one on that, but who is going to argue and say that being environmentally conscious is a bad thing?

Of course, if your engine is not the “V” style engine, then you will be removing the cylinder head from the engine to find out what happened to make water and oil get mixed. To sum it up, if water is mixing with the oil in your car’s engine then there is a leak in the water jacket of the engine that is letting the water spray into the crankcase. Other things that will cause this to happen, besides leaking intake gaskets (on v style engines) and head gaskets, are cracked engine castings, like the intake manifold, cylinder head, or even the engine block. Normally if the engine block gets a crack that allows water and oil to mix, it is in a cylinder wall.

Now you have a better idea of what to look for, when water and oil start mixing and your engine oil looks like chocolate milk. Just because water and oil are mixing, it does not always mean that you have to rip the heads off. On some engines it can be fixed with a $15 gasket, and about 1 hour worth of work. It should only take an hour if you are also the only one who is watching the barbecue pit, with having to wash your hands every time you tend to it, and all that.

If your engine is running hot, then you will want to read how to diagnose an overheating engine. The first thing to look for is air in the cooling system, so here is how to bleed the engine cooling system. If air keeps getting into the cooling system for no reason then you might have to diagnose a cracked head. Other causes of head problems would let themselves be known by white smoke from the exhaust. Of course, water in the oil does not have to mean head problems, so make sure to read about different causes of water in engine oil. If you do not use Anti-freeze, or engine coolant then you should know what to do when water freezes in your engine. If you live up north then you will definitely want to know how to install a block heater in your vehicle, for all those cold mornings, too. Remember, if the Radiator comes out to have different temperatures, it could be dirty, or it might be time to change the radiator.