Deuce Power Bleeder R4x4 Style

[m16ty]

All the power bleeder does is it allows one person to bleed the brakes (you don't need soldier B to pump and hold the brake pedal) and it insures you don't pump the MC dry. It is possible to bleed the brakes without fluid in the sprayer but you're going to have to keep tabs on the MC fluid level to make sure it doesn't run dry. If your MC runs dry you'll have lost everything you've done to that point and will have to start all over. It's much better to have fluid in your sprayer to refill the MC as needed during the bleeding process.

 

[peashooter]

DUAL CIRCUIT POWER BLEEDER ideas

What about us guys with dual brake systems.you cant get to the mc cap like that it is on the front end of mc and it is a plastic sealed cap.Any ideas would be helpful.

I found some Master cylinder resevoir caps that will mount to the late model A2 trucks with the dual circuit brakes. My intention is to build a power bleeder similar to the single circuit units sometime but not sure when I'll get to it. So here is the info on the caps in case someone wants to beat me to it.
They are DORMAN part # 42044 and come with 2 caps but no gaskets, the set cost me $5 from Oreilly auto parts. The picture below shows the caps. The cap on the upper right is the stock cap from my truck. The only difference is that these caps say "use only Dot 3" which you can scratch off or whatever.

The MC resevoir also has a 1/4" flexible plastic ventline that comes out of it and (on my truck) goes up to the firewall area by the steering column. So perhaps using these caps isnt the best way to go about building a power bleeder since you would have to plug the vent line. Perhaps just tapping into the ventline closer to the M/C is that way to go?
If anyone builds a power bleeder for the dual circuit system, post it up here as I'd love to see it. If/when I build one I'll be sure to post it as well.

 

[clinto]

I found some Master cylinder resevoir caps that will mount to the late model A2 trucks with the dual circuit brakes. My intention is to build a power bleeder similar to the single circuit units sometime but not sure when I'll get to it. So here is the info on the caps in case someone wants to beat me to it.
They are DORMAN part # 42044 and come with 2 caps but no gaskets, the set cost me $5 from Oreilly auto parts. The picture below shows the caps. The cap on the upper right is the stock cap from my truck. The only difference is that these caps say "use only Dot 3" which you can scratch off or whatever.

The MC resevoir also has a 1/4" flexible plastic ventline that comes out of it and (on my truck) goes up to the firewall area by the steering column. So perhaps using these caps isnt the best way to go about building a power bleeder since you would have to plug the vent line. Perhaps just tapping into the ventline closer to the M/C is that way to go?
If anyone builds a power bleeder for the dual circuit system, post it up here as I'd love to see it. If/when I build one I'll be sure to post it as well.

Much thanks to Peashooter for his assist here. I have a customer's M35A3 here that needed a system flush. Here's what I did:

Using the aforementioned Dorman 42044 caps and the Dorman 420814 gaskets, I built a pressure bleeder adapter for the firewall mounted M44A3 reservoir.


I took the new cap and drilled a 15/32" hole in the center. Be advised you can probably make the hole a little larger, like 31/64" or perhaps even 1/2". I wanted the air fitting to screw in very tightly.

I then screwed a Milton M-series 727 fitting into the cap. This will work with the factory fitting on your Motive Power bleeders and is the most common quick disconnect out there.



On the bottom, I used JB Weld to ensure no air or fluid could escape from where I'd mounted the quick disconnect fitting or through the small vent line that is molded into the bottom of the caps.

You'll also need to cut out the center of the gasket, so brake fluid can get into the reservoir.



After doing this, I was able to get up to 12 lbs of air pressure (psi obviously) without the cap leaking brake fluid. This is more than enough to properly bleed and/or flush the brake system on an M44 series (A2 or A3) truck.



If you have the three fittings shown below, you can bleed any M44 series truck except the 1987-1989 dual circuit USAF A2C's. I will show how to do those in the near future.

 

[m715mike]

Doing it R4x4 Style!

This thread is great! Thank you Recovry4x4 for starting the discussion and posting the pictures!

Using Recovry4x4's pictures, I purchased a one-gallon sprayer at Home Depot and everything else from my local hardware store. They can be more expensive, but I like to support the local stores. I acquired all of the parts and assembled the sprayer today. The breaks on my truck will be bled next weekend.

The table below shows my parts list and the associated cost. I had to purchase everything except for the air line quick couplers, which I had already.

The parts are listed in order starting with the sprayer and ending at the master cylinder cap:

HDX 1-Gallon Multi-Purpose Sprayer	$9.97
1/4" ID X 1/4" MPT Hose Barb	$2.99
1/4" Chrome Ball Valve	$13.99
1/4" X 1-1/2" Red Brass Nipple	$2.99
Air hose quick coupler - Female	N/A
Air hose quick coupler - Male	N/A
1/4" ID X 1/4" MPT Hose Barb	$2.99
1/4" clear tubing (2' in length)	$0.66
1/4" ID X 1/8" MPT Hose Barb	$1.79
0-100 PSI Pressure Gauge	$13.49
1/8" Brass Tee	$5.29
1/8" X 5" Red Brass Nipple	$4.79
1/4" - 5/8" Hose clamps (3 @ $1.99 each)	$5.97
Total cost	$64.92

 

[m715mike]

Here's a tip from the old school brake guy. When you open a system on the deuce and you know that the system has air in it. Pick one wheel far away and bleed it untill you get that mass of air out. From there bleed the rest of the system. I see the novice deuce brake bleeding guys don't wait long enough on that first wheel and get the air split up in several lines!

I still have a question after re-reading this thread. There will be air in the line on the power bleeder from the sprayer tank to the master cylinder cap when you first pressurize the sprayer tank. Does this air cause an issue? I assume that the air will be injected into the break system on the truck. Is the solution to simply "get that mass of air out" by first bleeding at the right rear wheel cylinder? Is there a better technique?

 

[frank8003]

I like mine, commercial, wasn't much. and I use a NAPA tube check valve thing on the bleed fitting.

 

[wilfreeman]

It doesn't cause a problem. I try to fill the MC all the way to the top and put the cap back on and make sure there is fluid all the way out to my quick connect before I hook it up. No problems doing it this way for the last 1.5 yrs

 

[Recovry4x4]

The air will accumulate at the top of the master cylinder. As the master cylinder pressurizes all the air will rise to the top. You won't push air through the fluid already there!

 

[wb9btz]

A giant THANK YOU to Recovery4x4, Clinto and Peashooter for this thread and the contributions made to it!

I had to replace all 4 brake lines on the rear axles of my M35A3.

By using the information provided in this thread, I was able to successfully and singlehandedly bleed the brakes on my Deuce in a very short time.

The Steel Soldiers community is wellspring of information and advice if one will only search for it!

Thank you again gentlemen!

 

[Doug Roberts]

did you ever do one for the USAF A2C ?

 

[2deuce]

I have the same question, can a power bleeder be used on a 1987-89 USAF deuce. If someone has done it, I think another cap would have to be found. The original plastic cap is flimsy.

 

[2deuce]

Possibly a quick change adapter or hose barb could be placed through the cap with a washer and nut. Some silicone to seal or if there is enough room o-rings. Anybody know the part # for the cap?
Thanks

 

[2deuce]

I found a cap at my local Napa. It was exactly the same as the original except it had different writing on the top that said to use dot 3 fluid. I incorrectly thought the cap was flimsy, it's thin, but rigid enough to thread a 90 degree barb for a hose attachment. It took some time because I used a bit that was as small as possible and still turn in the fitting. The problems I encountered are the cap is vented under the rubber gasket and through the side of the cap. I tried to use some silicone sealer under an o-ring but the o-ring didn't seal well enough to the top of the MC so it leaked. An o-ring could work that was properly sized to the MC, but I'm 60+ miles to where the truck is so I wasn't able to experiment. While the cap is vented the system doesn't use that vent. There is another vent on the MC with a hose that terminates in the engine compartment. I found this out when I cut a hole in the cap gasket and used it and more sealer. Without a hole in the gasket, brake fluid can't be pumped into the MC, and with the hole in the gasket I was able to pressurize the MC. That's how I discovered that vent line. Now if you could pressurize the vent line, I believe the system would hold pressure and you could power bleed the brakes. As it was I pinched the vent line and resumed bleeding, but my silicone seal didn't hold in the cap, because when I took the o-ring out of the cap because it wasn't sealing, and installed the rubber gasket back in the cap, I also had to re-seal the cap with silicone and it wasn't dry enough and failed. So I had to go back to pumping the pedal. Being so far from the truck makes experimenting difficult. I did get a good pedal, but I still have old fluid in there I want to change. Plus the dash light stays on indicating a fault. I'm wondering if I could have a a hard pedal with only have half (front or rear) brakes working. The parking brake is also not working so that could be the reason for the light remaining on. I've got more work to do.

Thanks
The odd thing I have't figured out with this truck is why there was air in the system in the 1st place. There is no sign of leaking wheel cylinders, actually no sign of leaking anywhere.

 

[peashooter]

Possibly a quick change adapter or hose barb could be placed through the cap with a washer and nut. Some silicone to seal or if there is enough room o-rings. Anybody know the part # for the cap?
Thanks

It’s all in post 22 & 23
https://www.steelsoldiers.com/showt...r-R4x4-Style&p=1512754&viewfull=1#post1512754

 

[2deuce]

the napa cap I used is 675-1204. It is the same as the original with the vent in the side of the cap. The dorman cap looks to be the same on the outside, but does it have the vent built into the cap? If not it would be better than the original because it wouldn't leak out that side vent line in the original and the napa cap. Anyway the next time I'm at the truck I'm going to try to figure out if both circuits are working and why the dash light remains on and whats up with the parking brake, because it doesn't hold.

Thanks

 

[2deuce]

Update- I hadn't been to the truck in a week since I bled it and had a good pedal. The good pedal is now gone. The odd thing is when I push the pedal to the floor and release it I hear gurgling in the MC. Not a little bit but A LOT of gurgling. I did a smell test of the fluid I bled last week. It smells like dot 5 to me and is a dark amber, where the fluid in the MC is a greenish yellow. I think the prior owner (fire dept) changed the labeling on the truck to use Dot 3 only, and just added 3 to the 5 that was in there. As was suggested earlier...I'm now going to rebuild the entire system and go back to dot 5. Does anyone have any suggestions where to get wheel cylinder kits, a MC or a kit? I'm not sure if I'll try finding rebuild kits for the air packs of or have them done, by a shop. Advice is appreciated, as I haven't done this job before.
Thanks

 

[davidb56]

Dot 5 is purple. I got my Wheel cylinder kits from Big Mikes along with a set of shoes, seals, and boots. Boyce has them too. I pulled the front wheels and drums off, and everything was new inside, so I just changed the boot. on the inside boot clamp I cut it down about a 1/2 inch and slide a piece of 1/8 inch tubing over the threaded end to prevent possible rubbing.