How safe to tow a Deuce with another Deuce?

[TexAndy]

You guys are incredible.

Ok, I need to do some research on brake system parts and what I need to order. Also, I'll go ahead and get a tow bar, just in case we can't get the brake issue resolved on the lot.

The yard guy was nice too. Said he'd help me try to prime the system.

Could the problem be as simple as a leak somewhere in the master cylinder, ie when I press the brake pedal, there's no line full of DOT 5 for the piston to push against so no resistance to the brake pedal?

eta: Ah, I see keith's explanation.

If so, how difficult is it to remove the master cylinder and replace whatever gaskets or seals need replacing?

Keith is a great guy people. steelsoldiers got the smartest person I've ever met when he joined.

13F10 is quite generous as well. Really, this site is awesome. I'm constantly amazed with the helpful attitude, donation of time, and wealth of knoweldge displayed by the members here.

 

[Keith_J]

The part that is probably leaking is the little cup. It is rubber, prone to wear and aging...rubber gets hard then the cup won't seal...when they are soft and new, the pressure makes them seal even tighter. This cup only travels over a short length of the cylinder, normally. But if the brakes are worn and not adjusted (drums, each shoe has its own adjustment), then the brake pedal must be depressed further, causing the cup to travel over a rougher, unused part of the cylinder and that causes more wear/leakage. You won't notice any leak because it is all within the cylinder and no loss of fluid is noted. Sometimes, you can raise the pedal, then slam it down and possibly get it working BUT you should ALWAYS repair!!! 7 tons of steel needs all the brakes to work at 100%


Back in the Army, we would just replace the whole master cylinder, then bleed the system. For a pair of hung-over full bird privates (Sp 4) on a Monday morning, it is a one hour job. One time, we didn't have a spare in the PLL and I didn't want to use leather personnel carriers (boots) so I found a cylinder hone and managed to overhaul the MC in my deuce (bumper number B14). The cup was fine, it was just dirt.

I saw the overhaul kit for $24 and change. Has the boot, spool, spring, cup and check valve.

 

[m16ty]

I wonder if a 7 ton capacity trailer with an 8 foot wide bed could safely haul one of these things?

That depends.

Most 7 ton trailers are rated for 7 tons gross weight. That means the weight of the load and the trailer can't go over 7 tons. Most gooseneck 7 ton trailers weigh about 4,000lbs so you can only haul 10,000lbs or 5 tons. There are some bumper hitch 7 ton lowbed trailers and I wouldn't even consider one of them. If the trailer is actually rated for 7 tons of payload then you should be ok as the deuce weighs just under 7 tons.

 

[m109]

remember to check the trailers weight

 

[GoHot229]

I see your in Texas, I say tow it, heak stop every 25 miles and check it out, it's only a 2-3 hour deal coming back, if that, take it easy, it should be a non event really.

 

[comanderfritz]

i have a question... i might need to tow a deuce with another deuce for about 20 miles but i have no tow bar. was thinking of using chain and a 2nd driver to steer. could this be done legally? i have done this with smaller vehicles but not sure if it is legal...

 

[Keith_J]

i have a question... i might need to tow a deuce with another deuce for about 20 miles but i have no tow bar. was thinking of using chain and a 2nd driver to steer. could this be done legally? i have done this with smaller vehicles but not sure if it is legal...

Bad idea. Brakes will be sluggish, even if hydraulics and shoes are in perfect order. Tow bar or do not do it. The correct tow bar is a heavy beast, attaching to the shackle pads on the front of the towed vehicle and to the pintle hook on the towing vehicle. And turning the pair will be difficult. I have seen a broken pintle hook on the towing vehicle with complete loss of the towed vehicle.

 

[m16ty]

I wouldn't attempt flat towing a truck without a towbar unless is was just at slow speed off road. I have done it but it was back when I was young and dumb .

 

[frodobaggins]

i have a question... i might need to tow a deuce with another deuce for about 20 miles but i have no tow bar. was thinking of using chain and a 2nd driver to steer. could this be done legally? i have done this with smaller vehicles but not sure if it is legal...

Not legal anywhere I know.

 

[mkcoen]

The seal in the master cylinder is a simple cup, the return force on the pedal is from the wheel cylinder brake shoe return springs. There is a spring in the air booster/valve unit (for the air brake system) but these are all simple air-boosted hydraulic brakes.

quote]

I let Andy know at the Alamo MVPA meeting today that I have an NOS master cylinder that he can have or scrounge parts off of if that's what's needed. Anyone in the San Antonio area is also welcome to come out and tinker on my stuff if they don't have any of their own yet and just need a green metal fix. I've got the M35, M37, M1009, and a diesel generator that can always use a little more loving than I can give them.

 

[Orionspath]

All great replies. I too believe you can do this if you are sure your truck is in great shape and the road is managible. As Brian said, it would be incredibly helpful to get a buddy to assist. I have had to call on a few in my day during retrievals. ON THE OTHER HAND, your smoling deal of $770 W/W, would still be the sweetest if you had someone pick it for you......Me, I'd go and get it myself! You just cannot compare the satisfaction of bidding, winning, and retreival. Now i really understand how my wife feels when she comes home from shopping the sales......

 

[Keith_J]

The seal in the master cylinder is a simple cup, the return force on the pedal is from the wheel cylinder brake shoe return springs. There is a spring in the air booster/valve unit (for the air brake system) but these are all simple air-boosted hydraulic brakes.

quote]

I let Andy know at the Alamo MVPA meeting today that I have an NOS master cylinder that he can have or scrounge parts off of if that's what's needed. Anyone in the San Antonio area is also welcome to come out and tinker on my stuff if they don't have any of their own yet and just need a green metal fix. I've got the M35, M37, M1009, and a diesel generator that can always use a little more loving than I can give them.

AWESOME! This is better than maintaining a complete PLL. I am pretty good at rebuilding master cylinders. My parents had a 1954 Chevy, getting brake parts was a chore but rebuild components were easy and cheaper to ship.

I realize a rebuilt unit isn't equal but it beats the wait.

Yes, I might just take you up on the wrench spinning offer, once it gets cooler. Isn't much cooler in Spring Branch.

 

[TexAndy]

Keith, you should also consider joining the MVPA. We're going to do a military vehicle show the 26th of September. There's going to be at least a dozen military vehicles there. Including a half-track with mounted .50s!

 

[mkcoen]

Yes, I might just take you up on the wrench spinning offer, once it gets cooler. Isn't much cooler in Spring Branch.

If you don't mind working on a M1009 I have it inside the air conditioned shop. Unfortunately the deuce will not quite fit in there.

 

[Warthog]

Hey TexAndy,

I recovered a Deuce from Ft Sam that had no brakes.

15 minutes and a gallon of brake fluid later the brakes where good to go.

I made my own bleeder very simular to this one. Mine cost me about $20 in parts.

http://www.steelsoldiers.com/deuce-modification-hot-rodding/34614-pressure-bleeder.html

Warthog

 

[Keith_J]

Hey TexAndy,

I recovered a Deuce from Ft Sam that had no brakes.

15 minutes and a gallon of brake fluid later the brakes where good to go.

I made my own bleeder very simular to this one. Mine cost me about $20 in parts.

http://www.steelsoldiers.com/deuce-modification-hot-rodding/34614-pressure-bleeder.html

Warthog

Sweet. Just got back from DRMO at Ft. Sam to help Andy. MC was bone dry, a pint filled it with lots of bubbles, I bled the booster, then each WC, some were clogged. The truck had the yellow silicone brake fluid sticker but the stuff bled out was yellow. Passed the taste test for silicone...I am thinking it might have mixed content which caused failure of the seals.

We didn't get a good bleed or there is a leak in the system. When we get back in a few days, check the level again to see if it has dropped, if so we will have to tow it to a storage lot and fix the brakes. I didn't have a bleeder containment jar and didn't want to make a mess even though the truck is on a pad of absorbent (cat litter). Will bring that next time

It could also be worn shoes. I would like to try the pressure bleeder, that makes the most sense although a full MC and a regulated air supply works fine too as does my el cheapo portable battery-powered tire inflator, it is slow enough.

The Deuce should be running in a week, come hell or high water. Since I am in town and Andy can bribe me with goodies, it will get fixed.

 

[Keith_J]

Ok, had a brainstorm session while fishing...since I think I got a good bleed job but still a soft pedal, the brakes could be horribly out of adjustment. With too much distance, the displacement of the MC is insufficient to cause the WC to extend and make contact.

What if I were to put a few PSI of pressure via air into the MC through the breather fitting? If this stiffens the pedal, then it is an adjustment issue. Since DRMO/GL won't allow a 3 axle brake adjustment, I could rig off a compressed air line, tee in an adjustable regulator and then slowly increase the regulator setting to in effect, "adjust" the brakes? This would be stopgap measure to get it off the lot and off post to somewhere we can do a proper adjustment.

 

[TexAndy]

Frankenbrakes... I like it...

What's involved in adjusting the travel of the WC's?

 

[Keith_J]

Frankenbrakes... I like it...

What's involved in adjusting the travel of the WC's?

It is called adjusting the brakes. It sets the minimum the retract spring will pull the shoes from the brake drums, there is a "snail adjuster" on the forward and aft parts of the backing plate.

The wheel is elevated on jack stand and transmission is placed in neutral. All other wheels chocked and each shoe adjusted until it drags, then backed off just a hair. Repeat for the other shoe, then again for each wheel. See page 13-62 on the pdf TM available here.

Hydraulic brakes operate on the same principal as a hydraulic jack, the pedal can make a LOT of pressure but very little volume. Since the brake has only a single stroke, this tiny volume must move all 6 wheel cylinders, meaning 12 pistons, one for each shoe, against the drum. That means if the shoes are worn, there will be a lot of volume lost forcing each of the 12 pistons to contact the drum before any force can be made.




As far as a spare air line...page 13-155 shows a connection on the right side of the cab. This is usually the connection for filling the tires. This is where we can connect the air regulator for our DRMO "adjustment" of the brakes.

 

[emr]

A Major brake adjustment is adjusting the top and bottom of each shoe to 10,000 at the top and 20,000 at the bottom , it takes a few times to get em on, then about 3000 miles they are suggested to have a minor brake adjustment just doing the tops, then anmother 3 a complete major again, My spongy pedel 12 years ago made me replace master, air pack , and still had, it, finally a master sgt, came to my shop and showed me how to and about the crrect way, I got a major adjustment and the peddle was like new...