1965 D100 Master Cylinder

[Fargone]

So the master cylinder on my '65 D100 is starting to leak into the cab. It seems that the MC was only used on the trucks in 65 and 66 and is out of stock at a lot of the major suppliers.

The 1964 D100 used a similar looking MC as the '65 and it was used on many models of trucks and cars and is readly available. Anyone know what the differences are between the two MC's?

I am having a hard time findinglisting of the bore of my present MC to rebuild and was wondering if I could use the "64 stlye without modification?

Thanks

[martincom]

I'd give some serious thought about moving to a dual master cylinder. It is a vast safety improvement, as if you have a hydraulic failure on one set of wheels, you still have brakes on the other.

My first car was a '64 Dodge Coronet Wagon. The right front wheel cylinder failed without notice. I had absolutely no brakes. The emergency brake did not work, as the cables were rusted up, a common problem in MN were they generously apply road salt as a de-icer. I was approaching a busy intersection where I did not have the right of way. I managed to get it slowed own by downshifting and some quick steering into a grocery parking lot and down an alley. I finally got it stopped-----three blocks later. I was blessed that I was able to get it stopped without incident. It could have easily became a horrific tragedy.

You may a spend bit more, but I'd suggest you give the Ram Man a call and see what he recommends for a dual cylinder replacement: https://therammaninc.com/

[Wildergarten]

So the master cylinder on my '65 D100 is starting to leak into the cab. It seems that the MC was only used on the trucks in 65 and 66 and is out of stock at a lot of the major suppliers.

I'm with martincom: Unless this is a totally stock restoration, a later model double master cylinder is a necessity. If you do choose to install one, the TGR Professional Brake Line Flaring Tool makes making double flares easy. The special tube fittings that fit into the master cylinder or other fittings downstream are avaialbe on ebay. The neutral safety switch should be avaiable at a wrecking yard as almost all late 60s early 70s switches are the same. I did this one as a 20 yo kid with virtually no experience with cars with wrecking yard parts. Well worth the trouble.

[Fargone]

Thank you for the replies.

The truck is an original example of the '65 D100 and I would like to keep it close to original as possible. Brakes are something I don't skimp on, all parts are basically like new, that is why at the first sign on a leak on the master cylinder it is to be repaired.

My '65 is the most modern historic vehicle that I have owned by far, most of my vehicles have been from the 30's and 40's with 80 year old brake technology. If maintained properly properly these systems work fine.

[jeffc57]

master should be the same 62 to 66, I have 62 and it uses the same master as my 66 d100.

[martincom]

There is a fellow in MN that rebuilds the single cylinder brake and clutch master cylinders. He installs a stainless steel sleeve to repair pitted bores. I found this thread, I'm not sure if it is the same fellow, but they might get you taken care of: viewtopic.php?t=20163

[Wildergarten]

My '65 is the most modern historic vehicle that I have owned by far, most of my vehicles have been from the 30's and 40's with 80 year old brake technology. If maintained properly properly these systems work fine.

If that is your intention, the only other thing I can offer is that it is worthwhile to flush out the brake and clutch systems with methanol to convert them to DOT-5 silicone brake fluid. The silicone doesn't absorb moisture and become corrosive and it doesn't eat paint if it's spilled. This is especially true if the truck isn't driven frequently, as the brakes don't get hot enough to drive out that moisture. DOT-5 s good enough for the military, which has a lot of equipment that gets intermittent use and that's all the qualification I need.

[PwrWgnDrvr]

... If maintained properly properly these systems work fine.

Yes, until they don't....and then you're lucky if you survive!
If they were so great, EVERY mfr would not have stopped using them!

[Fargone]

master should be the same 62 to 66, I have 62 and it uses the same master as my 66 d100.

Just by going to Rock Auto to see what parts are year specific the '65/66 D100 models were the only units to use this RAYBESTOS MC36202.

In 1960-64 the D100 used RAYBESTOS MC36203 and all the other models of trucks 60-66 and lots of cars . Many equivilant brands made of this model as well.

[712edf]

I'm sure Ralph Nadar & the good ol gubermint had something to do with the elimination of single reservoir MC's in passenger vehicles in 1966.

Incidentally my 75 W600 came with one & still has it.

Bucky

[dodgeboykim]

I can tell you from experience that blowing a wheel cylinder on a single braking master cylinder system is not fun in traffic. I'm all for a dual braking system and my 66 was done back in 1983.

[PwrWgnDrvr]

I can tell you from experience that blowing a wheel cylinder on a single braking master cylinder system is not fun in traffic. I'm all for a dual braking system and my 66 was done back in 1983.

Yup!
Blew one in 73, on an 8 yr old 65 Fury 3 going down a steep @#% hill in CA at 20 MPH . Dragged the e-braked rear wheels almost a hundred yards before it stopped.
Blew one in 81 on a 62 IH 18' flatbed ton and a half truck backing a towed forklift downhill into a pasture. Got it stopped with the band style e-brake on the tranny, then drove it 3 miles out of the mountains using 1st and 2nd gears. Lost brakes 2 other times on it before I didn't have to drive it anymore (wasn't mine).

[soopernaut]

There is a fellow in MN that rebuilds the single cylinder brake and clutch master cylinders. He installs a stainless steel sleeve to repair pitted bores. I found this thread, I'm not sure if it is the same fellow, but they might get you taken care of: viewtopic.php?t=20163

I don't know if that email address for John Geidl is still active. His last contact info he posted was:
John Geidl 651 653 0147 or cjlapham44@gmail.com