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Wed Jul 03, 2013 12:29 pm

My 63 panel has IRS in the back and I put on Type 3 brakes but it has been nothing but a headache. Just last night they would get super tight after a little driving. The pedal would get rock hard and it felt like I was pulling an extra 1000lbs! Then it loosened up, ran fine? But they are super hot all the time. We used the micrometer and measured 100x and they shouldn't be rubbing? We've triple checked we have all the right parts and we've gotten them backed all the way off....any ideas?

I finally have it to a point I can cruise it and this is pissing me off!
PLEASE HELP. (of course the stock bus fronts work perfectly :!: )

Wed Jul 03, 2013 12:50 pm

are the soft lines good? when they get old they collapse and don't release the fluid from the wheel cylinder

Wed Jul 03, 2013 1:08 pm

joe56vw wrote: are the soft lines good? when they get old they collapse and don't release the fluid from the wheel cylinder

i bet that is it

Wed Jul 03, 2013 1:10 pm

soft lines for sure. only other possibility would be the tabs for the star adjusters on the backing plate missing, and the stars rotating and adjusting themselves in and out. but I'd bet on the rubber lines

Wed Jul 03, 2013 1:36 pm

Every single part is brand new, hard lines, soft lines, adjusters and all. The adjusters function normally too. It has been a real fight getting the drums on and off each time though, to the point I had to replace one because of cracking from hitting it too hard.

Wed Jul 03, 2013 1:42 pm

What else will cause that kind of issue, messing with the master cylinder rod, so it's not releasing just the rears? Could be I suppose, I never mess with that rod

the hoses could of course still be bad, new or not I suppose

Wed Jul 03, 2013 1:48 pm

roundhouse72 wrote: Every single part is brand new, hard lines, soft lines, adjusters and all. The adjusters function normally too. It has been a real fight getting the drums on and off each time though, to the point I had to replace one because of cracking from hitting it too hard.

if your rear brakes don't release, it would be hard to get the drums off.

Wed Jul 03, 2013 1:59 pm

I have had brand new wheel cylinders stick most of the new stuff is cheap Chinese crap

try taking the wheel cylinders apart and check the seals and plungers to see if they are good
the last set of cheap wheel cylinder I got I had to hone out the inside because there was machining marks that the plungers were sticking on

Wed Jul 03, 2013 6:55 pm

Make sure there is a tiny gap between the end of the brake push rod and the master cylinder piston. It has to have some gap.

Wed Jul 03, 2013 10:26 pm

BarryL wrote: Make sure there is a tiny gap between the end of the brake push rod and the master cylinder piston. It has to have some gap.

Yes, it is 1mm measured underneath or 10mm measured at the pedal.

Thu Jul 04, 2013 2:20 am

did you pay attention at the adjusters screw ends ? where the shoes are locked in place basically is different from the bus and that metal piece has an angle and will only go one way to allow the shoes to rest, if you turn it the other side even with the adjuster all the way back the drum will not fit or have way to little play..
So check the angle of the adjustment screw..
good luck

Thu Jul 04, 2013 6:57 am

Thanks guys, dad and I will check these things and let you know....happy 4th!

Thu Jul 04, 2013 11:29 am

Let us know
Happy 4th

Thu Jul 04, 2013 6:53 pm

roundhouse72 wrote: The pedal would get rock hard

It probably was just hitting on the ground and had no where to push to.

roundhouse72 wrote: and it felt like I was pulling an extra 1000lbs!

Cuz it was rubbing on the ground.

roundhouse72 wrote: Then it loosened up

Stopped over a sink hole?

Fri Jul 05, 2013 4:11 pm

:D funny...it's not THAT low!

Fri Jul 05, 2013 4:46 pm

EverettB wrote: BarryL wrote: Make sure there is a tiny gap between the end of the brake push rod and the master cylinder piston. It has to have some gap.

Yes, it is 1mm measured underneath or 10mm measured at the pedal.

I bet a dollar that this is the cure. I have had it happen when I replaced a M/C.

Fri Jul 05, 2013 4:55 pm

Pedal free play and what was said about the adjusters. If they are in wrong, they can actually cut into the brake shoe and hold the shoe farther away from the wheel cylinder and closer to the drum.

I have been victim of bad soft lines right out of the parts bin too. Don't discount them just because they are new.

Sat Jul 06, 2013 8:08 am

I had a master cylinder that would build brake pressure as I drove it until the rear brakes would get tight and lock up until I let it sit for a while. Found that the piston inside was not retracting back far enough to completely open the bleed port which let's fluid back into the reservoir. If you take it out and shine a light into the bleed port while pushing in the rod you should be able to see the piston seal go past it, it should not be blocked when off the brakes.

Sat Jul 06, 2013 9:59 am

Mile High Puma wrote: I had a master cylinder that would build brake pressure as I drove it until the rear brakes would get tight and lock up until I let it sit for a while. Found that the piston inside was not retracting back far enough to completely open the bleed port which let's fluid back into the reservoir. If you take it out and shine a light into the bleed port while pushing in the rod you should be able to see the piston seal go past it, it should not be blocked when off the brakes.

Pretty sure that this is exactly what happens there is not enough pedal/pushrod freeplay.

Tue Jul 09, 2013 6:31 am

Hey Guys....got back on the brakes this weekend and I think we solved the mystery. We changed out the shitty AutoZone "type 3" (I put that in "" because I think they are just a one size fits all BS part #) wheel cylinders with nicer German units. The difference was immediately noticeable, the AutoZone cylinders were 3mm bigger each side and were pushing the pads too far out then not releasing correctly. The size difference was only really noticeable when you compared overall length with the German cylinders.

Took it out for about a 20 minute cruise and got no pedal stiffening, no buildup of heat and it performed much, much better.

Thanks for all your help and suggestions, moral of the story is don't take the easy way and buy shit parts from local chains. Spend a little more and get the good stuff you can count on.