Few questions after hydroboost install

[696]

Ok, got the system on (all 84 replacement parts). I have the "brake" light on the dash but if I move the E-brake a little toward the floor it goes off. Did the hydroboost system mess up the adjustment (if there is one)?
The 1st half of the brake pedal is GREAT, barely push and it stops great, the halfway to the floor seems a little more spongy (yes I can push the pedal all the way to the floor). I can slam on the brakes and get a lock up but sometimes it slows quickly but will not lock up and it is NO WHERE near as solid as the 1st half. Air in the lines still or is that the way the system works? I did bleed the brake lines til the fluid was the new clear brake fluid but only really got air on the pass rear cylinder (the 1st one we bled). I bled the power steering system by working it side to side and I guess the air is out (no bubbles). The only other thing is I hooked the system up 3 days ago and filled up the brake and power steering fluid then it sat til today when I bled both systems.
If the system is suppose to be this way fine but I want to make sure this is the way it's suppose to be.
Thanks,
696

 

[TurboBuRick]

There has to still be quite a bit of air in the system.The pedal should not go to the floor. Fluid does not compress.

 

[jdpolzin]

Yep, too much air in the system still. The brake light is coming on because the sensor in the porportioning valve is sensing a lack of pressure. You may want to bleed the master cylinder before you bled the brakes and then bleed them the whole way through with someone else inside the car.

 

[696]

Ok, I'll look for some more air. We bench bled the master cylinder before installing it and Thumper gave me an idea for line bleeding. How can you tell if all the air is out of the power steering system? Or can you?

 

[jdpolzin]

Ok, I'll look for some more air. We bench bled the master cylinder before installing it and Thumper gave me an idea for line bleeding. How can you tell if all the air is out of the power steering system? Or can you?

Dont worry about the power steering. Just turn the steering wheel a bunch of times and it'll work the air out of it. The most important is going to be getting the air out of the brake lines. This seems to be the problem everyone has almost everytime they have their brakes apart. Do it with two people the old fashion way. Push the pedal, hold it, open bleeder, close bleeder, let go of the pedal...........over and over and over again. Start with the passenger rear, then drivers rear, then passenger front, then drivers front.

Make sure to keep the reseviour full so you dont suck any air into while your bleeding the brakes.

Also, make sure to cover the reseviour with a towel so you dont have any brake fluid splash on the paint.

 

[turbonut85]

JDP is right...sounds like air. Just out of curiosity, how does the pedal feel when the car is off?? Does it feel normal? (hard and high) Did you use a GM booster or a reman? The brake light on the dash indicates air in the brake lines...like stated above...I have a feeling you have more than one issue here...If you "slam on the brakes" with a properly functioning HB it will lock up ALL 4 tires while throwing you toward the steering wheel...EVERY time.
---For the brake light:
--BLEED-BLEED-BLEED!!! Use the old fashioned procedure that Jdpolzin described above.
--Check the E-brake switch adjustment.

---For the spongy feel:
--check the ps fluid level
--bleed the ps system by turning the wheels peg to peg twice and then check the fluid level again.
--try another booster

---Keith

 

[696]

Pretty sure it just air in the lines. Busy weekend so I plan on starting the gravity bleed tonight and go from there.....still they are better than the powermaster.

 

[696]

Master Cylinder may be crapped out.....DANG remanes one!!!

 

[696]

Ok, I'm messing with it now and with the car off I do get a hard pedal but lots of play til about 1/2 stroke, then it get stiff. With the car running it has resistance all the way thru the pedal but I can shove it to the stopper. I disconnected the switch to the proportion valve and the "brake" light stayed on. I disconnect the switch to the e-brake and the "brake" light went off. E-brake out of adjustment??? Or does the power for the switch to the proportion valve run off of the e-brake???
When the system IS working properly how should the pedal feel when the car is running and when off?

 

[696]

I pulled off the lower covering of the dash to look at the e brake switch and saw that it was not in contact with the brake lever. For the "brake" light to be off the switch has to be pushed up to break the contact. I'm not sure if my switch is out of position or if a piece broke off and caused the light to come on. I'm attaching a couple of pics of the switch and if someone could tell me if it's normal or short on the bended end.
BTW when I lift the brass piece of the switch up and break contact the "brake light does go out.

 

[696]

After reinstalling the e brake switch I'm 99% sure it has a piece broken off. There is no way it can catch in the teeth of the e brake to break the contact and keep the light off unless you move the switch WAY down. If you adjust the switch up enough for it to make contact with the back part of the e brake (to ensure the connection is made when you do engauge the e brake) and release the brake, it cant catch the teeth and shut off. BUT... the light is off now

 

[jdpolzin]

With the brakes working properly on a hydroboost system, you'll have literally 1/4" of pedal then it will be very stiff and grab like all H E Double hockey Sticks. There is still a problem here somewhere. I'm thinking something isnt valved right on the master or hydrobbost. But......Yes the E brake is definately where the light problem is coming from from. We are getting there slowly!

 

[696]

After fixing the "brake" light I do have pressure on the pedal with the car off about a 1/4 to 1/8 before touching the firewall. When I start the car I feel pressure all the way thru the stroke (no slack, as soon as you breath on the brake pedal it starts to slow) but I can push it to the floor. As soon as I let up it snaps right back, the car slows QUICKLY but almost seems like ABS rather than lock up. Push it to the floor and you stop (it does throw you forward) but it seem like it should lock up the tires as fars as the brake moves. I'm going to check the fluid levels tonight and make sure don't have any leaks (I shouldn't cause when the cars off the pedal gets stiff and doesn't move) but I' triple check.

 

[turbonut85]

After fixing the "brake" light I do have pressure on the pedal with the car off about a 1/4 to 1/8 before touching the firewall. When I start the car I feel pressure all the way thru the stroke (no slack, as soon as you breath on the brake pedal it starts to slow) but I can push it to the floor. As soon as I let up it snaps right back, the car slows QUICKLY but almost seems like ABS rather than lock up. Push it to the floor and you stop (it does throw you forward) but it seem like it should lock up the tires as fars as the brake moves. I'm going to check the fluid levels tonight and make sure don't have any leaks (I shouldn't cause when the cars off the pedal gets stiff and doesn't move) but I' triple check.

Bad booster. I'd bet Jdpolzin's left nut on it. :biggrin:

Did you get a reman one or a used GM one??

One more thing you can try before you swap the booster....purge the return line from the booster. Unhook the return hose from the p/s reservior and route into a bucket. have someone start the car and GENTLY step on the brake....p/s fluid should flow from the hose into the bucket. Try this, and if you are getting fluid into the bucket, stop the engine, reconnect the hose, start the engine again and peg the steering wheel stop to stop and see if anything clears up. Post back results.....I bet its the booster though...

---Keith

 

[696]

Remaned one...will check and post.

 

[jdpolzin]

I'm going to have to agree with Keith but I would prefer to not have to un-attach my left nut! It seems like the booster isnt valved properly. Keith had the same problems when he first put his in. Almost sounds like the exact problem huh Kieth?

 

[regal81455]

LMK if it ends up a problem child, I may be able to help as Ive got a second hydroboost assembly that had the brake pedal actuator thingy broke off during shipping and is only good for parts now...

 

[jdpolzin]

Is that a used original booster regal81? Keith had the same issues 696 is having with newly reman booster and ended up putting the new booster internals into an original booster housing and it fixed the problem. We're thinking they are taking too much material out of the inside of the boosters when they are cleaning them which is making the clearences change and not allowing the booster to work properly. Or maybe it was just dumb luck!

 

[regal81455]

since i bought it used i have no real way to tell if its reman'd unless i should be able to find some kind of stampings on it that would identify it some way?? any thoughts? i was just trying to help since its here and I don't necessarily need it unless I find out the other one ive got is junk and would need parts but hey thats several months away and ill cross that road then

 

[696]

Knowing me....dumb luck