Project 2a (brakes lines, M/C, RPV) (Tranny rebuild)

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[Posimoto]

The PO thought he had a problem with the engine because it lost power in second gear and the temp gauge would read higher then normal. The problem wasn’t the engine it was the check valve in the master cylinder. Whoever did the front disc swap on this flattie fall short of a complete job and the front discs were dragging. There is a residual pressure valve (check valve) in the M/C that needs to be drilled out and a new check valve installed in-line.

 The check valve works by stopping brake fluid from draining back into the master cylinder. This keeps caliper pistons and brake shoes from fully retracting so the brake system stays primed. The original 2a single M/C has one ten pound check valve for both front and rear drums. The drums require more pressure to compensate for return-spring tension while the front calibers only need a 2 pound check valve. You only need a check valve if your M/C is at or below the calibers/wheel cylinders. I have heard of some that didn’t change their check valve after a disc swap without issue, but I suspect their check valve is weak and not working properly. One guy told me he didn’t have a problem until he got vertical and the brake pedal went to the floor.

When I was on a trail ride and needed to fill the M/C some there were surprised where the M/C was mounted so I thought I would post the location.

The M/C are mounted on the frame rail on 45 -71 CJs. There is an access cover to remove to fill, inconvenient to say the least.



Removing the M/C can be a task so I decided to refurbish the M/C without removing it. I will be rerouting the wires that are near the exhaust as well.



I removed the piston rod, piston, cap, spring, and check valve. I also removed the front “V” fitting and installed new washers.





Check valve



Check valve after drilling out the rivet.



Drilled out the check valve casing and tossed the piece on the left.



Residual pressure valves 2 & 10 pounds on coated lines.



I buy my line in 25ft rolls then cut and flare them.

[Crown Automotive - Jeff]

Chuck,
 If I had known you were around when I was attempting my 2A project, I never would have given up and probably drove you crazy!

 BTW, I got your message and will give you a buzz about those seats. Thanks and keep up the good work on all those CJ's!

[jps4jeep]

Might want to note that the Blue residual pressure valve is the 2 psi unit and is used primarily for a disc brake caliper and that the red residual pressure valve is the 10 psi is used for drum brake set ups.  Switching them around will not give you the desired out come.

I also mounted the master and booster under the drivers seat on the frame rail on my hot rod.

As always Chuck, great work!

[Ian]

that access cover reminds me of the access cover in my dad's '34 chevy.  i had to remove the wooden floorboard to get to the access panel to barely be able to reach an oil point for the throw out bearing.

small hands, all about small hands

nice work

[Posimoto]

Thanks for the kind words.

Jeff, do you still have the 2a or did you sell it?

John, thanks for pointing out the color of the valves although I did mention which ones go the drums and calibers I failed to mention the color.

To add, each valve has an arrow stamped on it for direction flow (arrow points away from the M/C. The most popular brand is Wilwood they sell for $20 each but do not come with fittings. I bought my valves at Gearhead Enterprises for $15 each shipped and they came with the proper fittings as well.

Ian, I plan to use a transmission funnel to fill the M/C but the one I had was very dirty and I didn’t feel like cleaning it at the time so I used an extra filler neck from a 2 gal plastic gas jug I had laying around which work really well. I could mount a plastic power steering bottle on the firewall and run a line to the M/C which I may do at a later date.

[jps4jeep]

No Problem Chuck, Just clearifing, I didn't notice if you mentioned that the red was for drums, you are one of the last people I would question the auto knowledge of.
I have a 2 psi on my rear brakes on my YJ, I think I got it from summit clearence, don't recall how much I paid, wasn't much, the hot rod has a 2 psi for the front and a 10 for the rear as well as a wilwood adjustable valve on the front.

[Posimoto]

Most I know buy wilwood at summit. I found the Gearhead valve on ebay then called the company and received the ebay price.

 

 

[Posimoto]

The M/C are mounted on the frame rail on 45 -71 CJs.

Side note: 45-66 CJs came with a single M/C. In 67 dual MC were mandated and the procedure is different. There is no need to drill out the check valve on the dual M/C simply remove the front brake line at the M/C use a sheet metal screw to remove the cap then remove and discard the spring and check valve. Re-install the cap and plum in your 2 pound RPV inline and your done.

The stock rear hose is 16” long for anyone who has a lift and would like to increase hose length I found a match with the correct stock fittings and 4” longer. The hose is sold by United Brake part # 31668.

[Posimoto]

I installed the lines and rear hose. I frame bled the M/C using an old 2ft brake line with fittings on the ends. I cut in half and screwed both fitting in and bent the lines into the reservoir.

I bought a vacuum bleeder a few years ago and thought it would be a good time to use it for the first time. It worked well the only thing I had to decipher is whether the bubbles were coming from within the lines or leaking in from the bleeder threads/plastic hose. It was easy to tell because the threads or hose leak bubbles are very small compared to the in-line bubbles. Some Teflon tape around the threads would help.

After I bled the lines I took it for a test drive and the brakes worked very well. I got myself vertical and applied the service brake the pedal stayed firm.  All is good with the flattie.

[Posimoto]

When I bought my 2a I knew there was a front seal leak in the tranny and chances are the bearing was bad as well. Last time I was out the bearing froze up so I decided to rebuild the tranny in hopes of making the run on the 21st.

If you think your going to see clear pics of the underside of this 2a for get about it, what your gonna see is 64 years of nasty grim, dirt, and oil. I had to dig to find bolts.

Removed the crossmeber/skid plate with 10 pound of grim.



T-case minus skid.



Typically the removal process would be driveshafts, speedo cable, brake cable, t-case snubbing rubber and bolt, control rods, clutch cable, t-case shift levers, cross member and then pull out the tranny and t-case as a unit.

The pin that holds the t-case shift levers was frozen so I had to separate the t-case from the tranny while the levers were connected. It took some patience while turn and tweaking the case as I benched press it off my chest.

As you can see in the pic, below although tight, the pin will come out with some work but in the case the pin was frozen. I know some that have used air hammers to remove the pin.



The main drive gear was next



After I removed the cotter pin then removed the nut by hand = not a good sign.



T-case removed from tranny





After about 10 mins with a 2 pound hammer and awl the pin is out.



True story, a friend of mine and owner of Advanced Automatic Transmission swore he would never rebuilt another D-18 after having a difficult time removing the lever pin.

 

[Ian]

congrats on getting the pin out posi! a lesser man (like myself) could have started cutting

[Posimoto]

It developed into a challenge 

[BiGdAdDeE]

I love my 3lb hammer.  I bet with that extra pound you could have gotten it out in 8min

Honestly I have no patience with that stuff at all.  I had to have Jason get my bolt out of my tcase after snapping a bit and an easy out inside of it too.  But with the same finess and get it doneness you have he finagled it out and saved me a few bucks

Good work.  

[Axle]

hope you get it done to wheel.

[mika401]

Posi is the equivalent to a motivational speaker for me to work on my 2A
Thanks for all the info, really