[moparbeme]

Just got done with putting all new brakes, rotors, wheel cyl.,pads and shoes,calipers, brake booster, and master cyl. Starting on the bleeding process and was wandering how to start. everything is new concerning the brake sys. Could one of you all give a run down of the do's and donts of this process. My boys has a mx race tonight so I think could be put in the 911 urgent file ( esp. when wife gets home from work and sees nothing done :CRY: )

 

[Hot Stuff]

Did you properly bleed the new master cylinder before installing it? If so, I would start by letting it gravity bleed. Open all 4 bleeders and let it sit for awhile to see if it starts to drip. If one starts to drip, close it and see if the others start.

 

[Shibbyutman]

Well, the first and probably most important thing to do is bench bleed the Master cylinder. If you take two stub lines and route them back into the top of the reservoir and pump until your heart is content, this is how to bench bleed. This should be done even before installation into the truck as getting the air out of the MC is quite a mofo because of the small port holes to intake fluid into the MC bore. We were always taught to start bleeding the brakes with the wheel furthest from the MC as this will get a majority of the air out and make things easier to do the rest of the wheels. Once you do that you should be more or less on your way to having a kickass brake system.

 

[moparbeme]

What about all that abs stuff that the lines go in and out of?

 

[moparbeme]

Should I bleed all that stuff as well?

 

[Shibbyutman]

The abs system will purge itself while you do the base brake bleed. It would be a good idea to find a dirt road or some place where you could activate the ABS 3 or 4 times and then rebleed the system to ensure all air has been removed.

 

[moparbeme]

What the heck is going on here!!! Can get good brake pressure with truck off, have good power str. with it running, bench bled m.s. until blue in face bled brakes with truck off with all fluid and no air. took wheel hubs off and checked for leaks and adjustment. Checked lines from front to back. With all that, no brakes when truck is running. What am I doing wrong!?!?

 

[Shibbyutman]

I think there are two lines going to a power boost system on your truck. I don't know for sure, if it would even be possible to swap them, but do you have the pressure going in the return side and the return going to the pressure side of the booster? or vice versa at the pump? I thought about that for a while the other night when you called and that was really all that I could think of that would suck the pedal to the ground and keep it there like you were saying. Other than that I am totally out of ideas. It has to be something wrong with the booster as you did say that you have good pedal with it off.

 

[mike uz]

Did this problem start befor you did your breake job?

 

[moparbeme]

yes it did

 

[Shibbyutman]

Ok I didn't get that part of it. Well, the only thing you haven't replaced yet is the hydraboost pump. Maybe a check valve or pressure regulator inside that is bad...

 

[moparbeme]

I think there are two lines going to a power boost system on your truck. I don't know for sure, if it would even be possible to swap them, but do you have the pressure going in the return side and the return going to the pressure side of the booster? or vice versa at the pump? I thought about that for a while the other night when you called and that was really all that I could think of that would suck the pedal to the ground and keep it there like you were saying. Other than that I am totally out of ideas. It has to be something wrong with the booster as you did say that you have good pedal with it off.

They are in the right place, the way the braces are and the way the lines are bent made it easy to put back.

 

[moparbeme]

Where is the hydraboost boost located?

 

[moparbeme]

Where is the hydraboost boost located?

Hydraboost pump that is.

 

[moparbeme]

Ok I didn't get that part of it. Well, the only thing you haven't replaced yet is the hydraboost pump. Maybe a check valve or pressure regulator inside that is bad...

I assume it has to do with the power st. pump. I can here a little air bubbling when I pump brakes. Did not pay much att. to it because I had good power steering. Could this be my problem?

 

[kstinson]

The hydroboost is right behind the master cylinder. You can follow the lines from the power steering pump up to it. I doubt the hydroboost is causing you a complete loss in brakes. It sounds to me like there is air in the system still. Just keep bleeding till its out. Manual says Master Cylinder, Combination Valve, RWAL, Right rear, Left Rear , right front wheel, and left front wheel.