Brake Question for M812 also Sam Winer?

[Andydieselpower]

Just finished adjusting all of the brakes on the truck. M812 bridge truck. Some were gapped kind of heavy and one of the front wheels actually had the adjustment cam completely off the shoe tab. All is correctly adjusted and working. We thought this would fix our low pedal feel a little but to no avail.

When the truck is off/no air pressure the brake pedal which has no slop in the linkage will plunge into the master cylinder approx 3" before any resistance is felt. The pedal is firm at that point and doesn't feel to have any leaks/bypassing. All wheel cylinder and lines are dry. Master cylinder is full of fluid. The truck running with full air pressure has the same pedal feel. Any ideas? Brakes in current state cannot even come close to locking up rear end on gravel.

Is this a bad master cylinder? I'm tempted to replace the air pack when I'm in there. The cheapest quotes so far are from Sam Winer for a new not rebuilt master cylinder and air pack. $95 master cylidner and $295 for a new airpack. Has anyone bought anything from them as I'm familiar with CSI and Clark but they were quite a bit higher.

Thanks again,
Andy

 

[Andydieselpower]

anybody?

I thought I would have some responses by now. I just want to make sure Sam Winer's parts have a good reputation around here. Any ideas on my brake problems would be appreciated also.
Thanks,
Andy

 

[DDoyle]

RE: anybody?

I have bought obscure items from Sam Winer in the past - IIRC, I dealt with Robert Zetzer there - I may not have spelled that correctly.

Everything I got was as described by him, and shipped in a timely manner.

Regards,
David Doyle

 

[Rattlehead]

RE: anybody?

Robert is the guy who does the mil surplus parts. Nice guy, and they are a good company to deal with, I have ordered many parts from them. If you order early enough, they usually get it shipped that day.

 

[Rattlehead]

RE: anybody?

If you are sure the shoes are adjusted correctly, will the pedal pump up? Possible air in the system?

 

[Andydieselpower]

Thanks David. Rattlehead- We bled each wheel and the master cylinder and air pack bleed screws and no bubbles. The brake pedal is firm once it goes to the firm spot and holds firm. I just don't like how the pedal goes 3" down before anything happens.

Andy

 

[jwaller]

will it pump up and get higher the more you try and use it or does it always engage at that same spot ?

 

[Andydieselpower]

brakes

It won't pump up any. The pedal engages at the same spot each time. We just order the master cylinder and air pack from Sam Winer so hopefully one of these fixes the issue.

How's the 250 turbo project coming along?