PT81PlymouthPickup Posted January 5, 2020 Report Share Posted January 5, 2020 I am in process of converting to front disc on my 1939 Plymouth 1/2 ton pickup. I've read where several have had good luck with the Jeep master cylinders. The AC Delco #18M957 (95-2001 Jeep Cherokee) has been successfully used by a few on here for disc / drum systems. This master cylinder has a angled reservoir which on the 95-2001 Jeeps the masters were angled up. When mounted level on our old trucks they can't be filled correctly and look wrong albeit they may work OK. Anyhow, I found another master cylinder that appears to be exactly the same with a level type reservoir. AC Delco #18M802 (97-2006 Jeep Wranglers and some Dodge Dakotas) Anyone have any experience with these? Sure looks like it may work? Quote Link to comment Share on other sites More sharing options...
CO54 Posted January 5, 2020 Report Share Posted January 5, 2020 I know there has been a lot of use with the Jeep MC's, from doing some research and some input from another forum member, I found a Corvette style that will work, provided the bore stroke is the same, a mounting plate still needs to be fab'd. 77-82 Vette, RockAuto PN# MC39052, this option is more original looking with a quick glance. Just my 2 cents. Eric Quote Link to comment Share on other sites More sharing options...
PT81PlymouthPickup Posted January 5, 2020 Author Report Share Posted January 5, 2020 I agree Eric, the cast iron MC's look better but these more "modern" ones do take up less room. I had adapted a cast iron split master off of an earlier Jeep that I shoe horned in there but the piston diameter was too small and resulted in too much pedal travel. I've heard the 95-01 Cherokee mc's work well? Quote Link to comment Share on other sites More sharing options...
CO54 Posted January 6, 2020 Report Share Posted January 6, 2020 5 hours ago, PT81PlymouthPickup said: I agree Eric, the cast iron MC's look better but these more "modern" ones do take up less room. I had adapted a cast iron split master off of an earlier Jeep that I shoe horned in there but the piston diameter was too small and resulted in too much pedal travel. I've heard the 95-01 Cherokee mc's work well? From what I've heard with from other's on the forum, the Cherokee MC's work well. I wasn't aware of the big difference in sizes. Quote Link to comment Share on other sites More sharing options...
Young Ed Posted January 6, 2020 Report Share Posted January 6, 2020 also remember the steering column was moved forward quite a bit in 48 giving the pilot house guys more room to work with for master cylinder swaps. Quote Link to comment Share on other sites More sharing options...
NiftyFifty Posted January 6, 2020 Report Share Posted January 6, 2020 My Jeep reservoir is straight up and down, not angled like pictured above. If anyone plans to use any “corvette” swaps, do a pile of research and don’t cheap out...90% of those kits they sell or aftermarket masters are junk, within the last 6 mo my buddies shop has put 2 brand new ones on and neither was any good. 1 Quote Link to comment Share on other sites More sharing options...
PT81PlymouthPickup Posted January 6, 2020 Author Report Share Posted January 6, 2020 15 hours ago, NiftyFifty said: My Jeep reservoir is straight up and down, not angled like pictured above. If anyone plans to use any “corvette” swaps, do a pile of research and don’t cheap out...90% of those kits they sell or aftermarket masters are junk, within the last 6 mo my buddies shop has put 2 brand new ones on and neither was any good. Might you remember the part # of the m.c. you used? Quote Link to comment Share on other sites More sharing options...
NiftyFifty Posted January 6, 2020 Report Share Posted January 6, 2020 No sorry, I never recorded that in my notes Quote Link to comment Share on other sites More sharing options...
CO54 Posted January 6, 2020 Report Share Posted January 6, 2020 Here's the link to the MC that 59bisquik used: https://www.speedwaymotors.com/Universal-Power-Manual-Master-Cylinder-1-Inch-Bore,4316.html FWIW. Eric Quote Link to comment Share on other sites More sharing options...
bkahler Posted January 7, 2020 Report Share Posted January 7, 2020 The Speedway motors mc is 8" long. The original mc on my truck is 6-1/2" from the mounting point to the end of the pipe plug. Unfortunately I don't have the steering column installed yet to know if there would be clearance issues. Quote Link to comment Share on other sites More sharing options...
CO54 Posted January 7, 2020 Report Share Posted January 7, 2020 1 minute ago, bkahler said: The Speedway motors mc is 8" long. The original mc on my truck is 6-1/2" from the mounting point to the end of the pipe plug. Unfortunately I don't have the steering column installed yet to know if there would be clearance issues. Keep in mind the 1/4" to fab a proper mount for the change. Quote Link to comment Share on other sites More sharing options...
bkahler Posted January 7, 2020 Report Share Posted January 7, 2020 4 minutes ago, CO54 said: Keep in mind the 1/4" to fab a proper mount for the change. Good point. 1 Quote Link to comment Share on other sites More sharing options...
bkahler Posted January 7, 2020 Report Share Posted January 7, 2020 Anyone know how long the Cherokee MC is? Quote Link to comment Share on other sites More sharing options...
rockingjd Posted January 7, 2020 Report Share Posted January 7, 2020 The mounting pattern in your picture looks to be the same as on my 49 1/2 ton. I used a Toyota Celica master cylinder. 86 to 89 no ABS. Opened up the meteric holes to fit standard bolts and it fits into the original bolt pattern. No adapter plate required. Quote Link to comment Share on other sites More sharing options...
PT81PlymouthPickup Posted January 7, 2020 Author Report Share Posted January 7, 2020 13 hours ago, bkahler said: Anyone know how long the Cherokee MC is? The length of the master cylinders in my photos are exactly 6 inches from mounting flange to front of master cylinder 1 Quote Link to comment Share on other sites More sharing options...
PT81PlymouthPickup Posted January 7, 2020 Author Report Share Posted January 7, 2020 3 hours ago, rockingjd said: The mounting pattern in your picture looks to be the same as on my 49 1/2 ton. I used a Toyota Celica master cylinder. 86 to 89 no ABS. Opened up the meteric holes to fit standard bolts and it fits into the original bolt pattern. No adapter plate required. Did you experience and increase in pedal travel after converting to the smaller bore toyota master cylinder? Quote Link to comment Share on other sites More sharing options...
bkahler Posted January 7, 2020 Report Share Posted January 7, 2020 14 minutes ago, PT81PlymouthPickup said: The length of the master cylinders in my photos are exactly 6 inches from mounting flange to front of master cylinder So even with a mounting adapter it's still slightly shorter than the stock MC. That's good to know. Thanks! Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted January 7, 2020 Report Share Posted January 7, 2020 I used a M/C from a 2002 Jeep Grand Cherokee in my 52. Works very well. There is enough room in your truck for one of these even with an adapter plate. One of the reasons I chose this M/C is that it is a direct match up to the Grand Cherokee rear axle I fitted. Having 12" discs in the rear is really really nice. With the rustyhope kit on the front and these discs on the rear my truck easily handles the silly drivers I have to share the road with here. I just don't have to worry about braking as the truck stops much like a modern vehicle. Also the 3.55 ratio axle works well in higher speed commuting that we have here in SoCal. This installation has been pretty much fit and forget. Hth, Jeff 1 Quote Link to comment Share on other sites More sharing options...
rockingjd Posted January 8, 2020 Report Share Posted January 8, 2020 I adjusted pedal travel and position by customizing the clevis and push rod length. 2 psi inline checks to make sure the calipers stay full. Jeep Grand Cherokee rear axle with disks and Scarebird front disks. No issues stopping. Quote Link to comment Share on other sites More sharing options...
bkahler Posted January 11, 2020 Report Share Posted January 11, 2020 On 1/5/2020 at 11:29 AM, PT81PlymouthPickup said: I am in process of converting to front disc on my 1939 Plymouth 1/2 ton pickup. I've read where several have had good luck with the Jeep master cylinders. The AC Delco #18M957 (95-2001 Jeep Cherokee) has been successfully used by a few on here for disc / drum systems. This master cylinder has a angled reservoir which on the 95-2001 Jeeps the masters were angled up. When mounted level on our old trucks they can't be filled correctly and look wrong albeit they may work OK. Anyhow, I found another master cylinder that appears to be exactly the same with a level type reservoir. AC Delco #18M802 (97-2006 Jeep Wranglers and some Dodge Dakotas) Anyone have any experience with these? Sure looks like it may work? Did you mount this master cylinder? If so how well is it working? I'm going to be buying a new MC for my truck now that I'm installing a Grand Cherokee rear axle and any details you can provide would be great! Thanks, Brad Quote Link to comment Share on other sites More sharing options...
bkahler Posted January 15, 2020 Report Share Posted January 15, 2020 I just ordered this 1994 Jeep Cherokee master cylinder in the hopes that it will do the job. I have not been able to find any listing that stated the mounted length so that still might be a problem. I should know tomorrow night whether it will fit or not. I do know it has the same piston stroke as my original MC and has a 1" bore. It also uses standard inverted flare fittings. Stay tuned...... 1 Quote Link to comment Share on other sites More sharing options...
bkahler Posted January 18, 2020 Report Share Posted January 18, 2020 Ok, I received that MC yesterday and can safely say it won't work in my B3B. It measures 8-1/8" or so from mounting surface to the opposite end. Way to long. I bolted my steering gearbox to the frame and took a measurement and the absolute longest MC that will fit is 6-1/2". So today I went to the salvage yard and bought a 2002 MC from a Grand Cherokee with 4 wheel disc brakes and it measures just under 6". I'll post pictures of the adapter plate that I'm going to make once it's done. Brad 1 Quote Link to comment Share on other sites More sharing options...
bkahler Posted January 19, 2020 Report Share Posted January 19, 2020 Took the first couple of steps in making the MC adapter plate. As near as I can determine the three mounting holes for the original MC form an equilateral triangle with sides of 2-5/8". The bore of the MC seems to be placed in the center of the triangle. The Cherokee MC has all three holes on the same line so it was just a matter of lining all the dimensions up and then making a paper cut out to test my theory. The mounting holes for the Cherokee MC appear to be slightly more than 3-1/2" apart so I used 3-17/32" as the mounting bolt pattern. The OD of the Cherokee MC is smaller than the original MC and measures a little under 1-3/4" and will be centered in the same place as the original MC. Using my milling machine with a digital readout I laid out the hole pattern with accuracy around of around .002" or so. I made the template out of 1/4" aluminum plate and will use alignment punches to transfer the holes in the template to the actual plate I'm going to be using. It will be much quicker and easier to do the actually drilling on a drill press rather than the milling machine which is why opted to make the template. Plus it will be easier to make extras Current plans are to countersink the two holes that mount the Cherokee MC and then use lock nuts to hold it to the adapter plate. I hope to use regular hex head bolts to fasten the adapter to the truck but will use socket head cap screws if there are clearance issues between the Cherokee MC and the three mounting bolts. I ordered some 3/8" thick aluminum plate to make the actual adapter plate. Ignore the size of my aluminum template, it's just a piece of scrap 1/4" aluminum plate I had laying around. It will probably be a week or so before the 3/8" plate order arrives. I'll post more when I work on it again. Brad 1 Quote Link to comment Share on other sites More sharing options...
bkahler Posted January 19, 2020 Report Share Posted January 19, 2020 Any thoughts on this proportioning valve? This one is for front and rear disc brakes. Quote Link to comment Share on other sites More sharing options...
Tooljunkie Posted January 20, 2020 Report Share Posted January 20, 2020 Shiny... 1 Quote Link to comment Share on other sites More sharing options...
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