[Brad Anthony]

We purchased the RV 1 year ago and have replaced the rear brake lines, rear drum brakes, front disc brakes, master cylinder and have bled multiple times. It’s no longer leaking, it’s non abs, it uses a hydro boost system, but it’s still spongey and most of the time the pedal goes to the floor before stopping.

the front end is a 1986 GMC Safari and it’s built on a custom chassis that uses the existing brake lines, but extended for length.

we’ve fought this thing for months. 5 different mechanics have attempted to repair it and have failed. I feel like I’m drowning in this project and not able to stop. Any advice would be appreciated. Fingers crossed that someone knows how to fix it.

Brad

 

[AstroWill]

Welcome to the site Brad!

5 mechanics couldn't figure it out, must be a good one. I would think that everything that I have to say would have already been checked, but here we go.

No leaks... in that case the first thing I would check is that the rear drum brakes are done properly, out of adjustment or installed wrong will cause problems. This means primary and secondary shoes facing the correct direction, shoe contact points on the backing plate are lubed and don't have grooves worn in them, adjusters are installed on the proper side/direction/operating freely, and finally that they are adjusted properly.

As you pull it apart to check, take and post GOOD pictures of both sides, there are some very knowledgeable people on here that can tell something is off from afar. No such thing as too many pictures

I would also check the flexible brake hoses for condition/wear and if they expand excessively when the brakes are applied. Proper brake lines and fittings were installed?

 

[aquazen]

We purchased the RV 1 year ago and have replaced the rear brake lines, rear drum brakes, front disc brakes, master cylinder and have bled multiple times. It’s no longer leaking, it’s non abs, it uses a hydro boost system, but it’s still spongey and most of the time the pedal goes to the floor before stopping.

the front end is a 1986 GMC Safari and it’s built on a custom chassis that uses the existing brake lines, but extended for length.

we’ve fought this thing for months. 5 different mechanics have attempted to repair it and have failed. I feel like I’m drowning in this project and not able to stop. Any advice would be appreciated. Fingers crossed that someone knows how to fix it.

Brad

Air in the AB pump maybe?

 

[AstroWill]

Air in the AB pump maybe?

Doesn't have ABS.

 

[markmitch]

If it has hydroboost is the steering affected at all?

 

[Brad Anthony]

Thanks everyone. The van has no abs and no hydro boost. The drums were done recently and the mechanic seemed very insecure about his work. The shoes we so tight to the drum I could smell them and my rims were getting insanely hot. He then “adjusted” them and they still smell and don’t feel right. Could this small adjustment be the culprit? I have even rebled the system again and again.

 

[AstroWill]

All bad signs, drum brakes that are installed wrong or out of adjustment can use up all of the volume of the master cyl pretty quickly, this could be causing your issues.