M62 Master Cylinder

[WillWagner]

I need some help in regards to a MC on a M39 series truck. M62 Wrecker to be exact. We are in process of getting this up and running and stopping for use around the compound. I am working on getting it stopping. I have looked through the TMs we have in our library and the manuals posted here on SS, but they all seem to have the same thing. NO info on the master cylinder.

I pulled the MC from the truck and tore it down. I did notice that the spacer was missing at the rod end of the piston and when pulled apart, found no check valve and seal at the outlet of the bore.

We have a train car....a literal train car, two of them.....full of parts. There was another FE1575 master cylinder in one of them. It had the spacer, so, I pulled it apart to possibly use the casting since there are a couple of pitted areas in the original cylinder and the spacer. When this was disassembled, there WAS a check valve and seal at the outlet.

I went on line and started researching. I found conflicting info. Some places had kits that had NO valve and seal, some places had kits that HAVE the valve and seal.

My gut tells me that it should have one, but I figured i'd ask.

This MC is used on the A1-2 M39 trucks too, and I think on the 800 series, but they are diesel, this is R6602 powered, however, the braking systems are the same as in air assisted so it has an air pack and not a hydrovac like on an M8 so I don't think the check valve is in the air pack.

Does anyone have experience on these master cylinders and/or a diagram of the assembly?

First picture is of what came out of the cylinder that was in use on the truck, but was non op, second is the donor out of the parts train. The donor had a green tag, from the Army, stating that it was serviceable but in need of rebuild, which it is, it is very clean inside!

 

[foxtrot]

My first multifuel?

II just realized that it's not a 2.5 but a Serie 5-ton. Your comments are welcome.

www.steelsoldiers.com

Some photos pages 6;7;15.

 

[Guyfang]

I think ROBO has a M62, Not 100% sure, but lets see what he says.

@Robo McDuff

 

[WillWagner]

My first multifuel?

II just realized that it's not a 2.5 but a Serie 5-ton. Your comments are welcome.

www.steelsoldiers.com

Some photos pages 6;7;15.

I gotta say, you REALLY brought something back from the dead! It looks VERY nice, hope it drive as well as it looks. I saw air pack, but no MC, might have to go back through the thread because that was ALOT of reading.

 

[WillWagner]

I was kinda hoping @dmetalmiki would see this, I know he has an M62.

 

[dmetalmiki]

Get a re-build kit. And make sure it comes with the check valve.

Or, Clean and 'restore/ service' the master cylinder with the check valve yourself.

 

[WillWagner]

Get a re-build kit. And make sure it comes with the check valve.

Or, Clean and 'restore/ service' the master cylinder with the check valve yourself.

Very good! That's what I thought, but with kits with and without, It made me re think what I know. Thanks Mike!

It will be a mix and match, this will never see the road, just compound, but the binders need to work. The original MC piston and cup are good but the bore is questionable, however, with the installation of the spacer, it will most likely put the two cups out of the area that is pitted. The donor casting is perfect. I'll most likely use the donor casting, ck valve/seal, spring and spacer with the piston and cup from the original one.

Thanks again guys!

Wonder why the TMs skip over this part of the brake system?

 

[gringeltaube]

Wonder why the TMs skip over this part of the brake system?

I do, too.... being that everything else of the brake system is covered in great detail(!)

Exception: this old TM 9-2320-211-35 (pub.1964, last change C5 in 1978 ) shows this parts diagram and repair procedures (pages 248 & 249).
No mention of any check valve and/or spacer, though....

 

[US6x4]

FWIW - TM 9-2320-260-34-1 for M809 series dated October 1972. Air pack view lists a double check valve (item #2)

 

[WillWagner]

I do, too.... being that everything else of the brake system is covered in great detail(!)

Exception: this old TM 9-2320-211-35 (pub.1964, last change C5 in 1978 ) shows this parts diagram and repair procedures (pages 248 & 249).
No mention of any check valve and/or spacer, though....

View attachment 907122

Well, look, MORE conflicting info! The spacer would be "P" in the diagram. It is aps 3/16 thick and w/o it, the piston gets retracted far enough for the cup,(H), to move past the hole in the cylinder. We have the '78 manual, this is not in it!

 

[WillWagner]

FWIW - TM 9-2320-260-34-1 for M809 series dated October 1972. Air pack view lists a double check valve (item #2)

View attachment 907125

View attachment 907126

I think that valve is on the air side, but, if it is on the fluid side, that would explain why it isn't in the MC. I will roll under it and trace the system to see if it is air or fluid.

See, I was all set to go in Tuesday and assemble a master cylinder!

 

[WillWagner]

I just went back and reviewed the thread @foxtrot is posting. The dual check valve is indeed in the air side. Maybe he could chime in and let us know if there was a check valve in his MC, I know he stated it was messed up. Don't know if he refurbed it or just replaced it. One pic of it in an assembled state so I assume it was replaced.

 

[US6x4]

I think that valve is on the air side, but, if it is on the fluid side, that would explain why it isn't in the MC. I will roll under it and trace the system to see if it is air or fluid.

See, I was all set to go in Tuesday and assemble a master cylinder!

Item #18 is also listed as a check valve and that one may be on the fluid side...?

 

[WillWagner]

Item #18 is also listed as a check valve and that one may be on the fluid side...?

That is indeed on the fluid side and it looks to be on the outlet, going to the wheels. That leads me to believe that there should be no ck valve in the MC.

Good eye!

I am going to show this to the boss Tuesday and see what he thinks.

Thanks to ALL who have helped in this confusing ordeal!

I owe ya all a beer!

 

[Robo McDuff]

I think ROBO has a M62, Not 100% sure, but lets see what he says.

@Robo McDuff

Robo has an M51 Dump switchable to M62 Tractor, but the MCs are the same.

 

[WillWagner]

Robo has an M51 Dump switchable to M62 Tractor, but the MCs are the same.

Yeah, I got it figured out. M/C is rebuilt and in. Started bleeding things and then I did something that will require a few days off......my fault.

 

[Guyfang]

Lifting? Hammering? Playing rugby at your age?

 

[WillWagner]

Standing up........I am taking a brake for a bit until I can get advice/checked out. I do not want to get cut on again.

 

[msgjd]

I need some help in regards to a MC on a M39 series truck. M62 Wrecker to be exact. I went on line and started researching. I found conflicting info. Some places had kits that had NO valve and seal, some places had kits that HAVE the valve and seal.

Haven't been into the MC on my M62 but yours is a 1950's IHC as well as mine.. On the commercial truck side of things in the 1950's, IHC (and many others) used lockheed-wagner brake parts exclusively .. I have been deep into the brakes on almost every 1950's commercial L and R-model in my old former construction fleet.. Most all of them have the check valve you question, but not all.. Also, the CV usually was in the rebuild kits, but not all of those either.. I do not know why this was the case .. Get well soon !! That M62 will feel lonely, they don't like being ignored once they get someone's attention !!