Thought I would just start a build thread to keep all my questions in one place. The current plan is to go through all the major mechanical systems and make sure everything is in good order. Then move on to paint and then add any missing parts or accessories to finish it out. This will be a farm truck that gets used, so I'm not looking for show quality, but I would like things to be clean and stock where possible, with upgrades where it helps.
Starting on the brake system today. I ordered the MC and WC rebuild kits and the flexible hoses from the local CarQuest. My MC is dripping on the floor of the garage and the dust boot is ripped open. I'm currently working on getting the drums off to get all the WC's out (fighting those darn drum screws, just like the M715!!). I have no idea on the condition of the lines, but am not real interested in replacing all those at this time. This truck won't see much road time.
Well, I got the two left side wheel cylinders off.....yikes. I don't think I'm going to even attempt a rebuild. I've got some pictures of some nasty stuff coming out from under the cups I'll get posted.
So, I'm going to just buy all new stuff. Does this look like a good list (VPW part numbers)? I figured I could just reuse the inlet connections and bolts. I think the MC will be fine with a rebuild.
2 x 12:924206 Right Wheel Cylinder
2 x 12:924207 Left Wheel Cylinder
4 x 12:692166 Wheel Cylinder Inlet Connection Gasket
4 x 12:857309 Wheel Cylinder Inlet Bolt Connection Gasket
1 x 12:800001 Master Cylinder Repair Kit
3 x 12:926559 Front Brake Hose
1 x 12:922799 Rear Brake Hose
After getting everything rebuilt or replaced, I plan to pump a bunch of DOT3 through the lines until it runs clear. I realize the best thing to do would be either replace the lines or at least cleanse them with alcohol and switch to DOT5, but again, this will be a farm rig.
You are wise not to even consider rebuilding those wheel cylinders. They are waaay beyond salvation! Same goes for the rubber and steel brake lines. Since you have to replace all those parts anyway, it seems to me that replacing the master cylinder would be the thing to do. Unless it's as bad as the wheel cylinders, a rebuild would probably do the job. It's just that a new master cylinder would save you a little bit of work and give you the peace of mind that all brake components are new.
Hi Chicklin,
A tip to get your drums off. Pull the drums and hubs off as a unit, then seperate the hub and drum. I find it WAY easier than just pulling the drum.
The drum screws can be difficult, but heat will help things out. I use a drag link sicket, ground to fit the screws, in an impact gun. Take it slow on the impact or it will want to spin right out. Clean the slot as well as possible first.
Tim
Lifer wrote:You are wise not to even consider rebuilding those wheel cylinders. They are waaay beyond salvation! Same goes for the rubber and steel brake lines. Since you have to replace all those parts anyway, it seems to me that replacing the master cylinder would be the thing to do. Unless it's as bad as the wheel cylinders, a rebuild would probably do the job. It's just that a new master cylinder would save you a little bit of work and give you the peace of mind that all brake components are new.
I'm gonna replace the rubber lines and keep the steel for now. May do those later, but they are a huge pain and expensive in comparison.
I found a decent price on a whole MC, so I'm just gonna replace it. The one on there is in pretty decent shape (other than it's leaking), but I don't want to mess with it. If I just replace everything it ought to bolt right up, no problem. The only thing I will probably reuse is the brass inlet fittings (with new crush washers).
Last edited by chicklin on Tue Mar 24, 2009 4:06 pm, edited 1 time in total.
powerwagontim wrote:Hi Chicklin,
A tip to get your drums off. Pull the drums and hubs off as a unit, then seperate the hub and drum. I find it WAY easier than just pulling the drum.
The drum screws can be difficult, but heat will help things out. I use a drag link sicket, ground to fit the screws, in an impact gun. Take it slow on the impact or it will want to spin right out. Clean the slot as well as possible first.
Tim
I ended up just using a punch on the screws and they came out without really tearing them up too bad. Then a 2x4 and a hammer to coerce the drum off the shoes. These things have obviously not been off of there in a long, long time.
I've been doing my brakes also (nearly finished) and I went for total replacement.
Those "inlet hose gaskets" are the copper crush washers which may be had cheaper at your local parts store vs. VPW.
Make darn sure you blow out those old lines and check them for damage. Even if you had to replace a single section with off the shelf tubing, it would be worth it for peace of mind.
-John
Member of Dixie Division MVC
1953 USAF M37 wow, restored
1962 M151 Ford Production, on the rotisserie now
1953 USMC M37 w/w -in storage
1942 M6 Bomb Service Truck (sold to UK collector)
1967 M116A1 Pioneer Trailer
1968 M101A1 Trailer
S-89 Comm box
I agree with Refit re the steel lines. The "armor" on the original lines (and on new replacements) tends to trap dirt, dust, and other debris, which in turn absorb and retain water, resulting in rust. With lines that are 50+ years old, you could have any number of invisible leaks that will show up the first time you apply the brakes with all "tight" components. (Or it could happen the second time you apply the brakes...or the third...or the fourth. Point is, it will happen sooner or later, and always when you least expect it. I had the misfortune of rear-ending a police car at a traffic light when that happened with my '79 Cadillac. ))
Lifer wrote:I agree with Refit re the steel lines. The "armor" on the original lines (and on new replacements) tends to trap dirt, dust, and other debris, which in turn absorb and retain water, resulting in rust. With lines that are 50+ years old, you could have any number of invisible leaks that will show up the first time you apply the brakes with all "tight" components. (Or it could happen the second time you apply the brakes...or the third...or the fourth. Point is, it will happen sooner or later, and always when you least expect it. I had the misfortune of rear-ending a police car at a traffic light when that happened with my '79 Cadillac. ))
Yeah, I wondered about that. Seems like the "armor" is not very beneficial in the long term. I guess the military wasn't too worried about 50 year-old trucks at the time.
The armor would have not been a problem if regular maint. and cleaning were applied. Most of these trucks had a hard life after the military and then you add in bubba who runs in thick mud and never washes the thing.
-John
Member of Dixie Division MVC
1953 USAF M37 wow, restored
1962 M151 Ford Production, on the rotisserie now
1953 USMC M37 w/w -in storage
1942 M6 Bomb Service Truck (sold to UK collector)
1967 M116A1 Pioneer Trailer
1968 M101A1 Trailer
S-89 Comm box
My old lines were full of rusted goo. Dangerous!! and also that would get into my new brake cyls. and wreck them. And like Lifer said they could burst at any time. If you keep the original M/C you don't have the split system and will loose all your fluid at once so there goes your brakes. very dangerous.
A new set of brake lines aren't too expensive if you want the original armored type. I went with new lines from Vintage PW. But I wanted the original look.
Or you could just get Bendaflex lines at the autoparts store and bend up your own. Its easy stuff to work with and comes in pre made lengths. I made my new gas tank lines from it. Save the banjo fittings form the wheel cyls to reuse.
Just one last word on safety. I had to do a panic stop when a car pulled out in front of me and man I was glad to have goooooood brakes. IF my brakes had failed 6000 lbs of M37 would have smacked into the drivers door of the teenager's car.
My wheel cylinders were nowhere near that bad and I simply replaced all. Not worth the trouble and time expened to try and get one back to snuff. Replace and move on. I will need to replace my rubber lines one day, but I opted for the time being to run what I have. They are in pretty decent shape. Probably not the best idea, but so far no problems.
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