hydroboost problems

[gnloyalty877]

I bought a hydroboost unit and master cylinder from napa and can't get the pedal to feel firm. Me and buddy did the pump procedure to bleed and didn't have any luck. The pedal feels firmer when the car is off but when i turn the car on it almost feels like a rubber band when pushing the pedal down. All of the lines are hooked up correct and i can't figure what i need to do next. Any suggestions????

 

[BIG HEAD CHRIS]

Bleed em bleed em bleed em!!!! I had exactly the same problem,and it drove me absolutely nuts!!!!! When it was all said and done I just didnt get all the air out.I tried all kind of crazy stuff to get em to work and they just needed to blead. Everyone told me it was air,and I hesatated to believe them, but in the end bleed em again. Trust me, Bleed em!!

 

[jdpolzin]

Make sure you bleed the master first very well. If you arent getting any fluid out of the bleeders at the wheels, you have air in the master.

 

[gnloyalty877]

I just hooked up a vacula vacuum bleeder to them 5 minutes ago and pulled straigt fluid out of each wheel so i know there is no air in the system. I don't understand why when the car is off is have a better pedal feel and then i turn the car on and the pedal goes away and acts like a rubber band.

 

[charlief1]

I just hooked up a vacula vacuum bleeder to them 5 minutes ago and pulled straigt fluid out of each wheel so i know there is no air in the system. I don't understand why when the car is off is have a better pedal feel and then i turn the car on and the pedal goes away and acts like a rubber band.

Got a simple but stupid question for you Tyler. Did you get a rebuilt master or a new one? The reason I ask is that I've had so many problems with the rebuilt units I refuse to use them anymore. For some reason no one has a clue about doing a rebuld so I always buy new ones and save myself the headache.:smile:

 

[gnloyalty877]

I did buy the used one but would that cause the problems im having?

 

[charlief1]

For some reason the rebuilt units have problems. The last one I used was on my 85 Chevy 1/2 ton truck. I went through 5 and finally gave up and got the new one. It has to do with the bore and seals in the unit. Look at the master as someone presses down on the pedal (with the top off). If it shoots a stream of fluid up while it's being pressed slowly down then it's by-passing. This is a common problem with a rebuilt unit. It is not working right and you'll be much happier with the new one on it.

 

[TurboBuRick]

Did you adjust the back's?

 

[gnloyalty877]

All that happens when someone presses on the pedal is a bubble comes up sometimes and sometimes nothing happens so is that same thing.

 

[Blazer406]

It shouldn't be an issue since you used that fancy brake bleeder.... but did you bench bleed the master cylinder thoroughly? I have had great luck when I bench bled til I got good clear fluid stream back into the m/c. Without the bench bleed.....I could possibly see air still being trapped in that bore and getting bypassed when vacuum bleeding brakes.... just a thought. My luck bleeding when I didn't do a thorough bench bleed :redface: is much worse...... FWIW....

 

[gnloyalty877]

I bench bled the master pretty well but had trouble hooking the rear brake line to it so it leaked a little. I'll probably pull it off and bleed everything againa and see how it goes.

 

[charlief1]

I bench bled the master pretty well but had trouble hooking the rear brake line to it so it leaked a little. I'll probably pull it off and bleed everything again and see how it goes.

This may sound strange but force the pistons back into the calipers. This will back flush the fronts and force any air out of this section of the master.

 

[turbonut85]

Had the same issue when I converted. Sounds like the booster is the problem. Try bench bleeding the M/C again, and then the lines as well. If the problem persists, take the return hose off the P/S resivoir and put the open end into a bucket. Start the car and have someone GENTLY press the brake...P/S fliud should come out of the return line. This will purge the HB system. Hook the return line back up, peg the steering wheel side to side, and see if it clears up. Post up your findings. HTH ---Keith

 

[gnloyalty877]

Thanks for all the help guys i'll try all of your suggestions this weekend and post the results.

 

[grape of wrath]

Did you ever found out what the problem was?

 

[cruzn57]

sure don't have this problem with Vacumn setup!

but some people like the HB setup.

 

[turbonut85]

but some people like the HB setup.

Are you finished??

 

[cruzn57]

not yet

Are you finished??

need to go plow some fields , LOL