Dual Master Cylinder

dynodave · Post by **dynodave** » Sun Oct 25, 2009 9:14 am

Has anyone installed the dual Master Cylinder from Herm the Overdrive guy? If yes, what brake lines did you use? Do you have pictures? Did you remove the body or do it from underneath? Did you order the banjo bolt kit as well?

My master cylinder is leaking and I am planning on replacing it. While I am not doing an original restore, I want to keep it as original as possible yet safe. Any advice is appreciated.

Post by **wesk** » Sun Oct 25, 2009 11:42 am

No two conversions are alike. You will have to decide what length lines and type fittings you are going to use based on the condition of your present plumbing. It is really very simple once you decide what you will keep and what you will replace and how you want to split the original plumbing front to rear or diagonally. Herm's web site photos tell the whole story quite well. Except if you have an M38A1 or M170 then the placement of the master cylinder becomes a tough issue.

Did you review the installation description on the CJ3B page?
http://www.film.queensu.ca/CJ3B/Tech/Br ... aster.html

The brake lines you can buy ready made at the auto parts store just measure up the tube size of the old plumbing and the length you'll need and the type fittings and you are all set.

dynodave · Post by **dynodave** » Sun Oct 25, 2009 12:06 pm

Thanks Wes. Yea, I did review the site on the CJ, just wanted to know if anyone did it on an M38A1. I am worried about fitting it in there without having to do a chop job on everything.

maeserik · Post by **maeserik** » Sun Oct 25, 2009 1:01 pm

For my resto a few years ago, a specialist in brakes for oldtimers made all my brake lines with the help of the original ones. He could even delever the rubber lines between frame and axle. He used material from wagner, special for american cars. So custom lines in this case could not be a problem.

Erik

Post by **wesk** » Sun Oct 25, 2009 2:11 pm

I haven't located the old posts yet but there was a post a while back where the poster tried to put the kit in a M38A1 and found a serious interference problem with the frame because the CJ5 is not boxed all the way back to the firewall and the M38A1 rail is. I don't recall what the exact interference issue was, only that it was caused by the difference in the two frames. You should review the physical fitting of the bracket to your frame first to see if this will be an issue.

MODIFIED · Post by **MODIFIED** » Sun Oct 25, 2009 6:39 pm

I've read stories upon other sites of what you mentioned Mr. K. The existing frame Bracket that supports the stock M/C on the M38A1 would have to be eliminated and replaced with Herm's bracket. that apparently requires grinding removal of a Rivet which is a "bugger " to get to should one attempt this conversion with the tub mounted in place.

I think you might have some clearance issues with Brake lines in close proximity to the exhaust pipe. which is why Herm offers the banjo fitting.

Bill_F · Post by **Bill_F** » Sun Oct 25, 2009 6:39 pm

I put one in what is now rick L's jeep. It was not to bad of a job.

dynodave · Post by **dynodave** » Sun Oct 25, 2009 7:45 pm

Bill_F wrote:I put one in what is now rick L's jeep. It was not to bad of a job.

Did you do it with the tub on? In looking at the new bracket I can see how it may be difficult to do with the tub on. I would hate to remove the tub just to install a new Master Cylinder!

Bill_F · Post by **Bill_F** » Mon Oct 26, 2009 4:39 am

yes did it with the tub on but the engine and tranny where out.

davem201m38 · Post by **davem201m38** » Tue Oct 27, 2009 1:41 pm

Yes,
I'm on with this at the very moment. I've removed the body of my M38.

I did order the Banjo kit as there are problems this side of the pond matching up threads etc.

I have the problem of needing enough room for the PTO shaft to the winch, which as the pipes come out towards the PTO might be a problem.

I'm trying to keep the original brake switch, which not surprisingly is proving a bit of a headache; I'm sure I'll solve it.

My problem is fittting the standard M38 brake line and nuts into the oversize Banjo Bolts that come with the kit.

Still, I'm sure the nice hydraurics man will be able to help out, after he's stroked my wallet!

davem201m38 · Post by **davem201m38** » Tue Oct 27, 2009 1:44 pm

I forgot to say that; removing the tub isn't that bad given how much easier everything is to do with it off.
Hey Ho.
Dave

davem201m38 · Post by **davem201m38** » Wed Oct 28, 2009 10:01 am

BIG PROBLEM this side of the pond is finding reducers (adaptors) to make the 3/8 pipe nuts on the original brake line fit the 1/2 inch holes in the Banjo Bolt kit.

Anybody know a supplier or exactly what part this adaptor is?

Dave.

Post by **wesk** » Wed Oct 28, 2009 10:59 am

Hello Dave,

Can you post a photo of the parts in your banjo bolt kit.

If you want to retain the original stop lamp switch most folks go to the front axle "T" fitting and add a port for the switch. My choice would be to not rely on only half of my brake system for the stop light function. So, I would add a mechanical proximity switch on the firewall that would be open when the pedal is not depressed and closed as soon as the pedal's arm moves forward away from the firewall. These type proximity switches have a longer stroke/plunger then the switches used for interior door lamp activation in civvy cars.

Here's a good site to help sort out US inverted flare and "P" thread fittings.
http://www.smithfast.com/ifunel.htm