front pass. brake hanging up...

[rickywideglide]

i have a 1986 gmc crewcab dually, front pass. side caliper is hanging up,PO said he already replaced caliper,my first thought was to order new front brake lines, wow they did not make this very accessible,probably will have to destroy hard line to get it out, this line looks to run to proportioning block,any chance that could be the problem(proportioning valve),i saw a test to check valve using test light,driver side is not sticking.. any thoughts or ideas greatly appreciated

[87 STEPPER]

I know this is gonna sound like a PITA but I'd plumb a 0-100 psi gauge in the Pax brake line @ the caliper and see what u have for pressure then do it to the drivers side and go from there depending on your press differentials. If the pressures are the same or with in 5% I'd replace the caliper and the rubber flex hose on both sides.

Good luck.

[Firebirdjones]

Any time I've ever had a front brake hang, it's the rubber hose. Internally they collapse. The hydraulic pressure will force fluid through it and apply the brakes, but they won't release.

Cheap and simple fix.

[Shady Rascal]

Originally Posted by 87 STEPPER

I know this is gonna sound like a PITA but I'd plumb a 0-100 psi gauge in the Pax brake line @ the caliper and see what u have for pressure then do it to the drivers side and go from there depending on your press differentials. If the pressures are the same or with in 5% I'd replace the caliper and the rubber flex hose on both sides.

Good luck.

Bad, unsafe advice.

Originally Posted by Firebirdjones

Any time I've ever had a front brake hang, it's the rubber hose. Internally they collapse. The hydraulic pressure will force fluid through it and apply the brakes, but they won't release.

Cheap and simple fix.

This guy.

It's most likely going to be the rubber hose. Just like anything rubber, time takes it's toll. They delaminate and swell and plug up on the inside. Less than 20 bucks from the parts store per side to replace.

Use a flare nut crowsfoot and an extension to access the fitting inside the frame rail. Harbor Freight sells a set of the flare nut crowsfoot sockets for about 10-15 dollars that work just fine for this job. I don't often recommend Harbor Freight tools, but it's one of the few items that work well enough to accomplish the job in this case.

[mk3barti]

Rubber line. Just had this issue on my 76.

[Shugalou]

While your in there you might want to think about upgrading those lines to a stainless for improved performance.

[rickywideglide]

greatly appreciate the info, i had already bought the new rubber lines weeks ago,but getting to the fitting is difficult to say the least, i will try with the crowfoot but i guess if all else fails just have to bend up new line from proportioning block, thanks again

[Shady Rascal]

I changed several sets of hoses on these trucks using flare nut wrenches and various means to loosen those fittings inside the frame rails, with poor or mediocre results. Only when I bought the flare nut crowsfeet (even the ghetto HF ones) have I never had any more problems with them. Penetrating fluid, patience, and sometime a little bit of heat and they come right loose.