How to purge brakes

[davidbuick]

Hi everybody!

I'm new to this forum and the proud owner of a 97 Yukon with 55,000 miles.
I'm the first owner, and now after 10 year I had to replace my rear brake cylinder.
Now I have to purge the barke but..... I don't know how to do it.
When I open the bleeder and press the pedal, no liquid.
I'm Belgium and I have aked a few guy around here some have told me that I needed a special tool that goes into the abs modul and some that I needed a scaner with the proper program.
Any imput would be welcome, as my yukon is now on the side for more than 1 month.

Thank you

David Dony

 

[BigDogg88]

David,

Bleeding the brakes is pretty simple and you wont need any of the the above mentioned that you were told. What you will need is an open end wrench (size of the bleeder), brake fluid, and another person. If you dont want brake fluid all over you can also cut a small piece of hose to slip over the bleed and put it in a container. Now you want to start in the by bleeding the farthest brake away from the master cylinder... which would be the passenger rear. Have your friend get in the vehicle and pump the brakes (since the cylinder is empty have them pump like 10 times, or at least until you can see the brake starting to grip), on the last pump have them hold the brake pedal to the floor while you are under the vehicle loosening the bleeder to release any air bubbles. If you use a clear drain hose you will be able to see the bubbles come out... when there is no more fluid or air coming out, shut the bleeder and start the sequence over again. Do this until there is absolutely no more air bubbles coming out. Once youve finished the passenger rear make sure your master cylinder is still full and move on to the drivers side rear brake, and repeat the sequence as needed. Now, I take it you didnt put and front brakes on, but I would still bleed them. Start with the passenger front and then finish it up with the drivers side front.

Now i mentioned above that you will need to pump the pedal like 10 times before holding... well this is only on the brake that you put the new cylinder on... its standard to only pump 3 times and hold, so on the brakes that nothing was done to, just do 3. You dont want to wear out your friend that is doing the pumping.

I tried to explain this the best that I could, but if you need any more, reply and I will see what I can come up with.

Andrew Weeks

 

[davidbuick]

Thank you for the imput,
But that the standard procedure, working on all my car execpt the Yukon.
When I apply brake pressure or pump the pedal, no liquid is comming out.

I will have more info later from my mechanics.

David

 

[mightymouse]

There are supposed to be plastic caps on the bleeder valve.
They are sometimes discarded by unprofessional mechanics. Without the added protection, I have seen them get gummed up. A small stiff piece of wire, or a scratch awl inserted into the valve can clean them up enough to work.

Hope this helps.

 

[Mike97]

David,

Bleeding the brakes is pretty simple and you wont need any of the the above mentioned that you were told. What you will need is an open end wrench (size of the bleeder), brake fluid, and another person. If you dont want brake fluid all over you can also cut a small piece of hose to slip over the bleed and put it in a container. Now you want to start in the by bleeding the farthest brake away from the master cylinder... which would be the passenger rear. Have your friend get in the vehicle and pump the brakes (since the cylinder is empty have them pump like 10 times, or at least until you can see the brake starting to grip), on the last pump have them hold the brake pedal to the floor while you are under the vehicle loosening the bleeder to release any air bubbles. If you use a clear drain hose you will be able to see the bubbles come out... when there is no more fluid or air coming out, shut the bleeder and start the sequence over again. Do this until there is absolutely no more air bubbles coming out. Once youve finished the passenger rear make sure your master cylinder is still full and move on to the drivers side rear brake, and repeat the sequence as needed. Now, I take it you didnt put and front brakes on, but I would still bleed them. Start with the passenger front and then finish it up with the drivers side front.

Now i mentioned above that you will need to pump the pedal like 10 times before holding... well this is only on the brake that you put the new cylinder on... its standard to only pump 3 times and hold, so on the brakes that nothing was done to, just do 3. You dont want to wear out your friend that is doing the pumping.

I tried to explain this the best that I could, but if you need any more, reply and I will see what I can come up with.

Andrew Weeks

That's exactly right Andrew. The only thing I would add is to make sure that the person pumping the pedal does not release it until the bleeder valve is closed. Otherwise, air can be sucked back in through the bleeder. And remember to re-fill the master cylinder reservoir often.

David, if there is no fluid coming out you could have an obstruction in the brake line. If cleaning out the bleeder does not help, disconnect the brake line and have someone push the pedal. If there is still no fluid you will have to figure out where the obstruction is.