TRUCK MASTER CYLINDER UPGRADE ADVICE

[bkahler]

1 hour ago, CO54 said:

Glad the Wrangler MC worked for you!!!! One to keep in mind moving forward when there are clearance issues.  I'm still leaning towards the small booster/MC option for myself.  The vacuum is the issue with my planning, and possible execution. 

 

Well.....you just have to build an engine that really sucks.......! 

 

[kencombs]

1 hour ago, CO54 said:

Glad the Wrangler MC worked for you!!!! One to keep in mind moving forward when there are clearance issues.  I'm still leaning towards the small booster/MC option for myself.  The vacuum is the issue with my planning, and possible execution. 

I had been planning on a hydroboost with my firewall mounted pedals(56 PU, with 60 pedals/bellhousing), but I think now I have changed my mind again.  Probably a remote vacuum booster as it should be easier to find a location for a mount.    Lots of those available for the street rod crowd.

[JBNeal]

With everything adjusted, my brake pedal would only go about halfway to the floorboards, maybe a little more if I stood on it...I'd suggest a stop fab'd for the back of the brake pedal, but you're right about the need to floor a brake pedal means bigger problems are afoot...

[bkahler]

4 minutes ago, JBNeal said:

With everything adjusted, my brake pedal would only go about halfway to the floorboards, maybe a little more if I stood on it...I'd suggest a stop fab'd for the back of the brake pedal, but you're right about the need to floor a brake pedal means bigger problems are afoot...

 

Good info on the pedal stroke.  

 

It should be pretty easy to fabricate an add on bracket as part of the MC adapter.  Possibly even something TIG welded to the top of the adapter that would stop the pedal just before it contacted the reservoir.  Definitely something to think about.

 

 

[PT81PlymouthPickup]

On 1/11/2020 at 6:26 PM, bkahler said:

 

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

Wow! I started this thread a while ago, got sidetracked and have just returned.  Interesting discussion!  Anyhow, to answer your question; Yes, I mounted the Delco #18M957 (95-2001 Jeep Cherokee) master cylinder and No it won't work because on my truck the pedal hits the floor before achieving full travel of the m.c. That's a No - No. So, I've installed a cast iron one from earlier 84-89 Jeeps (Bendix 11896, Cardone 13-2409, Wagner MC105876). It's a little tight but adapted easily and allows full pedal travel. It has a 15/16 bore which I'm hoping will work well with my system? I chose this one because the 90 - 95 Jeep Wranglers uses a m.c. with exactly the same casting only a 1"bore. I figured it would give me the option to go to the larger bore if I have too much pedal travel and I would not have to re-plumb the lines. After much research about custom brake systems I've decided to use a adjustable proportioning valve and 10lb residual valve in rear circuit and 2lb in front. It's still in process, so I can't report yet how it will work out, but I am hopeful. I've attached some photos showing my mounting adapter which allows the rubber dust boot to be reinstalled.

[PT81PlymouthPickup]

Here's a few more photos.

[Young Ed]

that adaptor looks great!!!

[ggdad1951]

13 hours ago, bkahler said:

 

Good info on the pedal stroke.  

 

It should be pretty easy to fabricate an add on bracket as part of the MC adapter.  Possibly even something TIG welded to the top of the adapter that would stop the pedal just before it contacted the reservoir.  Definitely something to think about.

 

 

 

just be careful you aren't giving yourself a false positive on the brakes working....

[bkahler]

2 hours ago, ggdad1951 said:

 

just be careful you aren't giving yourself a false positive on the brakes working....

 

I'm not sure I follow what you're trying to say? 

[Tooljunkie]

1 hour ago, bkahler said:

 

I'm not sure I follow what you're trying to say? 

Say you had a brake hydraulic failure and pedal hits the stop. 
you may think there is still fluid pressure. It may not dawn on you until its too late. 

[bkahler]

2 hours ago, Tooljunkie said:

Say you had a brake hydraulic failure and pedal hits the stop. 
you may think there is still fluid pressure. It may not dawn on you until its too late. 

 

Ok, thanks.

 

If I put a pedal stop in it's going to be set so the pedal is just shy of touching the plastic reservoir.  It would do me no good to get full pedal stroke and take out the reservoir in the process

 

[Tooljunkie]

Agreed..

[BobK]

This ought to raise a few eyebrows  …… and I'm sure you will think I'm a  ……… but what if you just ding the reservoir   a little to get the clearance you need.  Maybe a little heat and bend, or cut a section out and JB weld a patch back in. Hey, I coulda' said duct tape the patch.  We notch cross members and oil pans for engine swaps, why not a MC reservoir?  But then that's why they have remote fill set-ups for MC.

 

It's a good thing I'm a horticulturalist,,,,,, and not a professional mechanic.

 

 

 

 

[DJ194950]

According to friend of mine any repair needed the first method he thinks of is- duct tape, not just any duct tape though, it needs to be that special-magical  tape as sold by Phil on TV!

 

Good for metal, plastic, glass, hose of all size/type etc.!

[Tooljunkie]

1 hour ago, BobK said:

This ought to raise a few eyebrows  …… and I'm sure you will think I'm a  ……… but what if you just ding the reservoir   a little to get the clearance you need.  Maybe a little heat and bend, or cut a section out and JB weld a patch back in. Hey, I coulda' said duct tape the patch.  We notch cross members and oil pans for engine swaps, why not a MC reservoir?  But then that's why they have remote fill set-ups for MC.

 

It's a good thing I'm a horticulturalist,,,,,, and not a professional mechanic.

 

 

 

 

If i had to relocate resevoir, it would consist of me machining parts that fit in place of resevoir and parts to mate resevoir to. Or just make up a  cylinder To hold brake fluid. 

[bkahler]

If for whatever reason I do end up going with a remote reservoir this is the one I would likely use, or something similar anyway.  It has the nostalgic look that I would want and provides decent mounting points.  And like TJ said I'd make my own parts to fit onto the MC.

 

For a little while I considered the idea of 3D printing my own reservoir but I'm not really up to the skill level yet to do something like that.

 

Brad

[Tooljunkie]

I like that, but a very clear label stating brake fluid only. P/s fluid destroys all the rubber in a brake system. I came across this a while back when a customer had brake trouble and no answers. Made an expensive mess. 

[bkahler]

45 minutes ago, Tooljunkie said:

I like that, but a very clear label stating brake fluid only. P/s fluid destroys all the rubber in a brake system. I came across this a while back when a customer had brake trouble and no answers. Made an expensive mess. 

 

I've not made that mistake myself but it wouldn't surprise me that it happens.  If I use a reservoir like that it would be mounted down low near the MC.  

 

I'm really hoping this Wrangler MC just works and solves all my problems!

 

 

[PT81PlymouthPickup]

On 2/9/2020 at 7:25 PM, Young Ed said:

that adaptor looks great!!!

Thanks Ed! I try to make things look good, but it doesn't always work out that way.

[Young Ed]

33 minutes ago, PT81PlymouthPickup said:

Thanks Ed! I try to make things look good, but it doesn't always work out that way.

Did you make it from scratch or start from something partially made? 

[PT81PlymouthPickup]

1 hour ago, Young Ed said:

Did you make it from scratch or start from something partially made? 

Made from scratch. I wanted to be able to reinstall the rubber boot to protect the back of the m.c. from dust, so I made one out of aluminum round stock as a prototype and then another out of stainless steel round stock. The alum. would have worked fine, but being too fussy for my own good I made another that will last forever. I am a machinist by trade and have access to lathes, mills, etc. which makes it a fairly easy project. Not sure why Mopar put the mounting holes on strange angles, but once you have them figured out, it's a basic lathe part.

Steve ?

[tinlizzy]

need to make some more of those adapters to sell.  I could use one and sure others would too.

 

[PT81PlymouthPickup]

The geometry would be different on the front side depending on which master cylinder is used. I have a drawing of the one I made if anyone wants it?

[bkahler]

On 2/9/2020 at 7:06 PM, PT81PlymouthPickup said:

Here's a few more photos.

 

Steve,

 

In looking at your pictures it seems that your Plymouth truck has more room in the area where the MC mounts.  Could you verify the length of the MC that you used?  I know for a fact on my 51 B3B there is only room for a 6-3/4" long MC.  I tried one that is 8" long and it was nowhere near close to fitting.  

 

I like your install, especially the idea of using a boot.  I'm going to see if I can find a boot that will slip over the end of the MC that sticks through the bell housing casting.  

 

Nice work

 

Brad

[PT81PlymouthPickup]

9 hours ago, bkahler said:

 

Steve,

 

In looking at your pictures it seems that your Plymouth truck has more room in the area where the MC mounts.  Could you verify the length of the MC that you used?  I know for a fact on my 51 B3B there is only room for a 6-3/4" long MC.  I tried one that is 8" long and it was nowhere near close to fitting.  

 

I like your install, especially the idea of using a boot.  I'm going to see if I can find a boot that will slip over the end of the MC that sticks through the bell housing casting.  

 

Nice work

 

Brad

Thanks Brad! Yes, the cast iron m.c. in my photos is exactly 8" long from mounting surface to the front. I'm fairly certain it will fit all 1939-47 Dodge and Plymouth pickups. Sounds like it won't work in yours? I was hoping the smaller Jeep aluminum master cylinders would work in mine, but the stroke was such that my pedal hit the floor before allowing full stroke of the m.c. I learned this could negate the purpose of a split system if you lose one half of the system from a hose or line rupture in an emergency situation.