Touchy brakes

[Sporin]

Wondering if you guys had any suggestions for adjusting my touchy brakes. The front id all new calipers and disks. Back is stock drums adjusted correctly and not leaking at ll.

I bled them, then had them gone through and bled by a shop in town so I'm reasonably confident they are ok on that front.

2 things happening....

1. I get very little braking on the top half of the pedal then BAM it brakes like I threw and anchor out.

2. Sitting at a stop the pedal can be pumped up but slowly goes down a long way before sitting solid, no rolling but unnerving sitting at the top of a hill.

Any ideas?

 

[Sporin]

If it's the master I'll probably just replace it with a new one, is there a readily available, recommended replacement from a different model or year that bolts right up?

 

[DesertLake]

The touchiness sounds like it could also be the booster.

 

[snailwagon]

I had the same problem in my 55. I upgraded to discs all around (was previously original single circuit, non boosted system). The pedal was very easy to depress, and would lock up the tires easily. It was like the brakes were all or nothing. Because the system I had experienced too much rear bias, it was really sketchy.

While trouble shooting, I had a friend press the pedal while running. I noticed the entire brake booster housing was flexing. I assume it was rusty inside, but I don't know, I changed it with a new junkyard unit and never had the same problems.

 

[Sporin]

thanks guys, appreciate the laundry list, so many things can go wrong in these systems, it's nice to have a list to run through. keep em' coming.

 

[Sporin]

Bleeding the rears really well seems to have cured a lot of what ailed it. The brake pedal is now MUCH more progressive and you get braking power right at the top and it steadily increases on the way down. Guess the shop I PAID to do that didn't do a very good job.

If you sit a long time at a light the pedal still slooowly goes down and stops, holds breaking though. I guess I'll replace the master at some point.

Thanks all for the tips!!!

 

[cruiser_guy]

Guess the shop I PAID to do that didn't do a very good job.

I stopped paying a shop to work on my brakes when they (major International chain) installed a bent caliper AND delivered the car that way. After the brakes wore out in 6-9 months they tried telling me that the cast iron caliper bent after installation?!?!