Dodge 3500 Master Cylinder Installed

[underDAWG]

Finally I replaced my stock TJ master cylinder with Dodge 3500 MC. It works beautifully.

It had been a struggle for more than 1 year since I switched to 35??s. My TJ did not stop the way it used to be, and the next stage of upgrade to 37??s is pending. While I was converting to Warn Full floater for my rear D44, I switched to Caddy rear disc also. Unfortunately, I didn??t notice any improvement on my brake performance. I then took the ??O-ring out, no observable difference. The pedal feel still made me uncomfortable. This went on more than 6 months. While there are many discussions on what works and work doesn??t. Unfortunately, there were so many contradicting results apparently due to many difference scenarios. There were great deal of debates on line pressure, proportional value, stroke volume and many other things. The debates are great and do enhance my understanding of my brake problem, but yet no viable solution for me until P4x4, Hunter from TX suggested me to use a Dodge 3500 truck MC.

I ordered a Dodge 3500 MC from the dealer. It turns out that the reservoir is too big for TJ, and most of the auto parts stores (Autozone, Advance Auto NAPA) do not carry one with the reservoir. Through BILLYCJ7, I got the part number form Bendix. I ordered mine from here: http://www.bendix-brakes.com/default.aspx

The installation could been easier; it was almost bolted in. I need to make a space about 7/8?? long. I used a 7/16?? bolt. The mounting holes on the Dodge MC is slightly bigger than the TJ MC mounting holes, so I put a couple O?? rings on the mounting studs so that the new MC will be centered. I also needed to grind the proportional value mounting bracket to clear the MC since its diameter is bigger than TJ MC. I bench bleed the MC and then bleed the whole brake system. I took a test ride, I couldn??t believe how nice the brake feel. Now the TJ handles like a BMW.

Here is the pic after the Dodge MC installed. On the right, it is the MC from the Dealer (reservoir is too big, otherwise everything is the same). I include the Bendix number too.



This pic shows the comparison between ZJ MC and Dodge 3500 Dealer MC. Dodge has is longer and slightly bigger cylinder.






BTW, I used to hate bleeding the brake system. With the Speed Bleeder, it is so effortless. Somehow, the trapped air is much easy to get rid of when compared to the wife/me method.

Later,
Linyee

[Darrell C]

All right, I just gotta ask: Speed Bleeder??

I hate bleeding brakes and anything (reasonable) that makes the process easier would be welcome.

BTW, nice job with the swap. Glad to hear it improved things...

Darrell

[underDAWG]

SB is just a bleeder has a built-in check valve. It replaces your stock bleeder. Just losen it a 1/4 to 1/2 turn, insert a clear tubing for catching the brake fliud. Press your brake gently and release slowing. The air bubbles will be gone in no time. I used to bleed over and over again. My wife was just sick of it, in fact my kids too. Now, one man job and 5 min of my time. It works everytime.

[ChrisK]

OK, I'm missing something here. The TJ MC has that engagement rod coming out of the back of the MC. The 3500 MC does not have one. What did you do about that or am I missing something?

Chris

[underDAWG]

Sorry Chris if I have not made myself clear in my original post.

Yes, the MC's are different. That is why I need to make a spacer out of a 7/16" bolt. The spacers is 7/8" long. I also rounded out the one end of the space to fit the bottom of the MC better. A small indentation (1/8" deep) was drilled out on the other end of the spacer for the pushrod to fit into. When you do yours, it will become apparent. HTH.

Later,

[ScottyY2K]

Linyee - Thanks again for the info.

We installed my Napa United MC last night. Worked out sweet. We did not finish off bleeding the brakes yet though.

Interestingly the MC that Fred (FAM) ordered from Dodge has a different reservoir than the one you origianlly got. His is the same as the one I got from Napa and fit just fine. I wonder if different distibution points in the US for Dodge use a different mfg. or something.

We tried a vacuum bleeder and it did not seem to work as well as this speed bleeder that you are talking about.

[mrblaine]

OK, you guys doing the 3500 M/C swap are confusing me to no end. I looked up the specs on that master and it has an 1 1/4" bore. Yes, that will give you a very high, very firm pedal. The consequence of that is that you have now reduced (in theory) the pressure to your calipers.

How is the actual braking performance?

I have experimented with the large bore masters on my hydroboost which generates much more force to the master than a vacuum booster ever will and was not happy with the pedal effort required to stop effectively. I had to drop the bore size down to 1 1/8" to get the pedal force reduced to a comfortable level and am considering dropping down even futher to 1 1/16" if I can find an easily bolted up suitable master.

Stock on the TJ master is 1", as you increase bore size in the master, you should be reducing the pressure to the calipers for a given input pressure from the booster. All other things being equal.

What gives here????

[ScottyY2K]

Originally posted by mrblaine
OK, you guys doing the 3500 M/C swap are confusing me to no end. I looked up the specs on that master and it has an 1 1/4" bore. Yes, that will give you a very high, very firm pedal. The consequence of that is that you have now reduced (in theory) the pressure to your calipers.

How is the actual braking performance?

I have experimented with the large bore masters on my hydroboost which generates much more force to the master than a vacuum booster ever will and was not happy with the pedal effort required to stop effectively. I had to drop the bore size down to 1 1/8" to get the pedal force reduced to a comfortable level and am considering dropping down even futher to 1 1/16" if I can find an easily bolted up suitable master.

Stock on the TJ master is 1", as you increase bore size in the master, you should be reducing the pressure to the calipers for a given input pressure from the booster. All other things being equal.

What gives here????

I can't answer your real question.

But..............I just got back from Moab. There are lots and lots of steep hills. We ran a ton of trails and the new brake set-up stopped the Jeep very well. I am VERY happy with it. I did not run my new set-up (wheels and lift) with the stock brakes but this feels much better than the stock brakes did with 33's. HTH!

[Daless2]

Hi Folks,

I personally don't have a need to upgrade my MC on my TJ at this time. (32's) but I can tell you from first hand experience, as soon as I bolt on a set of 35's my braking goes down hill fast.

Anyway, when I see thinks like this I like to make sure I understand them just incase I or a friend want to take advantage of the inventions of others. That said, can I ask for a clarification on part numbers and such?

As I understand it;

Linyee you used a MC for a Dodge 3500 Pickup Truck, Bendix number 13442

Questions:
Was this any particular year? Engine? Cost?
Ordering from Dodge Dealer resulted in getting MC with an incorrect reservoir to clear hood.
Ordering online from Bendix at http://www.bendix-brakes.com/default.aspx resulted in the correct MC and reservoir for $152.88????
Do you have the Dodge Part # that you originally ordered that does not work so we can stay away from it?


Scotty, you used a Napa United MC
Came with the correct reservoir.

Questions:
This was for the Dodge 3500 Pickup Truck as well? Year? Engine? MC Costs?
Napa Part Number??????


Thanks in advance guys. I'm just trying to make sure I can reproduce your efforts and get your results should I have to go down this path in the future.

Have a great day,

Frank

[ScottyY2K]

Originally posted by Daless2
Hi Folks,

....

Questions:
Was this any particular year? Engine? Cost?
Ordering from Dodge Dealer resulted in getting MC with an incorrect reservoir to clear hood.
Ordering online from Bendix at http://www.bendix-brakes.com/default.aspx resulted in the correct MC and reservoir for $152.88????
Do you have the Dodge Part # that you originally ordered that does not work so we can stay away from it?


Scotty, you used a Napa United MC
Came with the correct reservoir.

Questions:
This was for the Dodge 3500 Pickup Truck as well? Year? Engine? MC Costs?
Napa Part Number??????


Thanks in advance guys. I'm just trying to make sure I can reproduce your efforts and get your results should I have to go down this path in the future.

Have a great day,

Frank

Frank:
The Part Number:
NAPA United #390426 MC

There is a ton of other info on another thread....
http://jeepsunlimited.com/forums/sho...hreadid=379312

The truck was a 2001. It was interesting that we had three different MC's (Mopar, Bendix, and Napa) that all had the same reservoir and looked to be identical.

HTH!
Scott

[mrblaine]

If the larger bore master is actually working and I don't doubt the ones that say that it is, that leads me to believe that an entirely different issue is responsible for the poor braking on some rigs and not others.

I'm gonna do some more research.

[underDAWG]

Originally posted by mrblaine
OK, you guys doing the 3500 M/C swap are confusing me to no end. What gives here????

Blaine,

You may not know that I have been following your quest to get better braking performance for more than 9 months, because I have not been happy for my brake since I switched to 35? more than a year and half ago. I understand your argument, but yet there is no apparent solution to my brake problem.

Based on your experience as well as others here, I knew ZJ MC or prop value would not work for me. In fact I bought a new ZJ MC just for the heck of it. But I decided not to install. The 3500 MC came to me is a good alternative. For a mere $152 and about 2 hour or so, it was no brainer for me. The end result did make me happy. As you correctly stated, my pedal is higher and firmer. It travels less down as I try to stop. The effort to stop is relatively the same as before, but nevertheless I can stop quite well now.

In my situation, I used Caddy calipers. It is apparent that it requires more brake fluid to push the piston out. Even I took the O?ring out; it still had not had enough fluid to the calipers. Therefore a bigger MC did the job.

I looked up the specs on that master and it has an 1 1/4" bore. Yes, that will give you a very high, very firm pedal. The consequence of that is that you have now reduced (in theory) the pressure to your calipers.

I am quite sure I agree with you that I have lower pressure to my Caddy calipers. If I move the same amount of brake fluid out of the MC into the calipers, the same pressure will result. Now since I have changed to a bigger bore MC, in order to move the same amount of fluid, I only need to push a shorter stroke of the brake pedal. However, if I choose to push harder I will push more fluid out and thereby creates a greater pressure on the rotor. It has been so long since my College Physics days .

In theory, I should need to exert a pedal pressure to do that, but I found it not that bad at all. Now my quest is how I can have the booster do more pushing for me. Of course the alternative is to follow your foot steps to switch to the WJ caliper with bigger diameter rotors. Again in theory, the bigger the rotor will help. I am still waiting for either your or Chris L?s findings. I just received a pair of brand new WJ calipers yesterday. Man those are big suckers .

Please do not take the wrong way; you have my highest respect. My original post was not intended to pee on your turf or to undermine your effort here. A bigger MC will not solve the entire problem that most of us have, but it will at least address some of my concerns. We are all very successful in our chosen careers. Although I am not a fabrication guy here, I do read, think and analyze, and then I read some more and think some more again. That is how I make a living. Happy trails

[Daless2]

Originally posted by ScottyY2K
Frank:
The Part Number:
NAPA United #390426 MC

There is a ton of other info on another thread....
http://jeepsunlimited.com/forums/sho...hreadid=379312

The truck was a 2001. It was interesting that we had three different MC's (Mopar, Bendix, and Napa) that all had the same reservoir and looked to be identical.

HTH!
Scott

Thanks Scott, I appriciate the info and the link. Somehow I missed that one.

Frank