anybody have the power brake pedal return slow. have to pull back with my foot. any ideas

 

Yep, all 1906 Hupmoblies like yours had this problem.

Is it floor mount, on firewall, aftermarket etc. red, pink or purple, I think just a little more info is needed.

If there is no petal interference with anything you need a new booster.

 

this is a aftermarket firewall mounted brake system. what it does when i brake, the pedal feels hard not soft any easy like my car. when i brake a little harder the pedal is slow to release the brakes. I can pull the pedal back with my foot to speed up the release of the brakes. also have the brake light switch mounted to the brake pedal so the brake lights stay on longer. I downloaded some information from classic performance and they have some information on how to test the brake booster. i did go through there list and compared it to my car and it seems to work the same. I'm just wandering if it could be the master cylinder. classic perform says you need an adaptor between the booster and master cylinder. don"t know if there is one installed. I bought this unit as a kit from one of the outfits on ebay.

 

Let me think about this for a little, thanks.

 

Needs an adapter?? Does the booster mount your firewall 'over' one of the vertical firewall ribs?? You may need a 'spacer' between the firewall and booster to mount it solidly...You might be describing a booster push-rod adjustment scenerio...

 

Gallery said 1955. What brakes do you have in front and rear? Does the part number for the master cylinder match the disc/disc or disc/shoes? It makes a difference. Do you have porp. and other valves in the system. How did you bleed the system? Do you have the correct size diameter and length rod between the brake pedal and the master cylinder? Facts, etc we need to offer help. Thanks,chuck

 

ok, the front brakes are an 81 chrysler disc( volare suspension) and the rear is a 70 something ford 9 inch. the booster is mounted on the fire wall and seems pretty solid. although if I really bear down on the brake pedal I can see some movement of the booster/master cylinder. As for if the booster/master cylinder are matched for this aplication, I just am not sure about that.
I do have a porpotioning valve but I had to add an adjustable valve for the rear brakes as they would lock up before the fronts. I'm still in the adjustment stage.
As for bleeding the system, I did most of the work but had our local auto repair shop rebleed the brakes.
I'm thinking that I should just order a new booster/master cylinder for a disc/drun setup.

Dennis

 

Dennis, that might be a solution but not so fast, let’s make sure the booster is working or not first. With the engine off, pump the petal a couple of times to exhaust any vacuum in the booster, push moderately hard on the brake petal, hold down and start the engine, you should feel the petal move down slightly as the booster applies the brakes and if it does it is working. I think that all boosters have return spring for the diaphragm and if your booster is working but the petal is not returning freely (no binding) maybe the spring inside is broken? (doubt it) In looking on the net for illustrations of boosters I see that some also have a second return spring inside on the input (petal) shaft, not sure if yours setup uses one but it would do no harm to install one of some kind. I believe there is no direct mechanical (hard) connection between the booster push rod and the master cylinder so even if the MC was not returning (it has its own spring) the booster would / should still return.

Did you put a residual check valve (10 lb) in the rear system (maybe backwards) or are they in the proportioning valve?

See, the more info provided the longer the answers!

booster 2 (600 x 448).jpg

 

Ok, I did try all the test to check the booster, pumped pedal, started engine and pedal dropped 1/4 inch plus. there were a couple of other tests and i compared them with my car and it all checks out.
As far as a return spring I have added two to the pedal and that doesn"t seem to make any difference.
I don't have a residual valve just a combination (prpotioning) valve and a hand adjustable valve to the rear brakes.
I guess the booster could be working properly but still have a broken return spring.
This was installed about two years ago and has always worked the same. Might have been defective from the get go.
Dennis

 

Probably a bad ground!

 

bad ground, bad ground, bad ground. A sure sign of writing electrical manuals burnout.
Keep up the great work,chuck