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| | | | Joined: Jan 2008 Posts: 4 New Guy | | New Guy Joined: Jan 2008 Posts: 4 | I'm having no luck getting the rear brakes to work on a neighbors 55 GMC 350 series truck. I've bled the brakes numerous times but still no pedal. The master cylinder went out and I installed a new one but can't get the rear wheel cylinders to even move. But when I bleed them I get solid fluid. I plugged the rear line just before the rear wheel cylinders and have plenty of pedal. So I'm thinking the problem is in the rear. Any suggestions? Thanks,.... | | | | | Joined: Jan 2007 Posts: 176 Wrench Fetcher | | Wrench Fetcher Joined: Jan 2007 Posts: 176 | Either the rear brakes are way out of adjustment, or the wheel cylinders are seized
1970 C50 dump! saving orphans from the CRUSHER
| | | | | Joined: Nov 2005 Posts: 6,100 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 6,100 | Hy guys, I agree the rear brakes could be way out of adjustment, but if the wheel cylinders were siezed you'd have a good pedal but no brakes. | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | tmm,
Does your truck have a hydrovac unit? If so, did you bleed it as per the Maintenance Manual?
Tim | | | | | Joined: Jan 2008 Posts: 4 New Guy | | New Guy Joined: Jan 2008 Posts: 4 | I'd already adjusted the brakes earlier. Now this truck does have the dual wheel cylinders so is there a special way to properly bleed them? This has really baffled me. Also, I'm thinking if the local Napa store sold me the wrong master cylinder. Is there a difference from the pickup MS and a 2 ton version?
| | | | | Joined: May 2005 Posts: 8,878 . | | . Joined: May 2005 Posts: 8,878 | Is there a difference from the pickup MS and a 2 ton version? Yes, a big size difference. I would be surprised if you ever get the pickup one to work on that big truck, even with the brakes adjusted really tight... Grigg | | | | | Joined: Jan 2008 Posts: 4 New Guy | | New Guy Joined: Jan 2008 Posts: 4 | It does have the hydrovac unit but I did not bleed it. My thought was if I plugged the line beyond the unit and just before the rear wheel cylinders and had great pedal that the hydrovac wouldn't be the problem. Is that wrong for me to assume that? What is the proper way of bleeding the hydrovac?
| | | | | Joined: May 2005 Posts: 8,878 . | | . Joined: May 2005 Posts: 8,878 | Do you have a shop manual for the truck?
Grigg | | | | | Joined: Jan 2008 Posts: 4 New Guy | | New Guy Joined: Jan 2008 Posts: 4 | [quote=Grigg]Do you have a shop manual for the truck?
No I do not but I'm still searching,..
| | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | If the truck has the dual wheel cylinders with the shoes top and bottom, there is a special procedure for bleeding them. That is because the cylinders are vertical and the air doesn't get to the bleeder with the brakes adjusted normally. Read the procedure in the manual. | | |
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