1973 1210 power booster interchangability?

D

DISPATCHBDB

New member
I'm noticing that 1973 doesn't seem to have any brake booster/master cylinder combos available. The 1972 and 1974 years are available. I've checked most places. The question I have is.... Are the 1972 1210's booster and master cylinder the same? Or how about 1974's?

Any info would be appreciated. Thanks!
 
I see the 1974 3/4 tons have disc front brakes, maybe? So I guess those wouldn't work. But I still have a question about the 1972 1210's. Whats the difference between the 1973 and the 1972 braking systems.

My 1973 is drum fromt and rear with an I-beam fron axle.

Thanks again!
 
As near as I can tell, there is no difference in brake systems between model years '72 and '73. Parts catalog mt-131 covers '72-73 full size and motor home and makes no distinction between the two years with respect to the master vac booster assembly for the 1210 platform.
 
There are also companies that can be found via web search who will perform rebuild/reman services of your obsolete/hard to find booster if you would prefer to go that route.
 
I know I know....bringing back dead posts....but.....I just purchased a 72 345 1210 all drum brake pickup with 12x2.5's. It didn't have a booster so I got a remanned one with a cylinder and theres a number of issues. 1. The original shaft that attaches to the brake pedal is a loop on the original and a female straight open end on the new one. My mechanic is talking about cutting the loop off the old one and attaching to the new one....? 2. The hole where the original shaft went through the firewall is about 4 inches too high for the new part.....mechanic is saying well have to cut it open....? 3. The bolts don't line up, the original m/c has holes and the threads are coming off the firewall to place it on, the new booster has bolts attached to go into the firewall....so theyre opposite....
I cross referenced the part numbers for 1210 brake booster and they all show the same, one place said that his computer says they never even had power brakes.....
Im I in a mess with this? Im replacing all springs and calipers as well since im going to be towing 5k lbs I need stopping power!!
Thanx in advance!!:icon_up:
 
Typical response of a cookie-cutter parts shack with a pooderized d-base decades removed from the days when these dinosaurs roamed the earth. One thing we can put to bed is the notion that vacuum assist brakes weren't available for the full size rigs in 1972. In fact, that option was even available prior to '72. Double stamp it. Anti-quitsees. You can't triple-stamp a double-stamp, lloyd!

The problem you're encountering involves converting an original non-boosted rig to a boosted setup. This is a good news/bad news scenario. First the good. Most of the associated mounting hardware between a non-boosted 1210 versus a boosted rig is the same. Now the bad. There are several critical items specific to the vac assist setup that are either vastly different from the corresponding non-assist part or not used in a non-assist setup. The biggies here are the reinforced mounting plate on the engine side of the firewall, the pedal plunger rod, and a booster mounting brace.

The assist mounting plate has holes drilled through it to accept the brake booster along with a center hole to accommodate the plunger rod.

The plunger rod in an assist setup has a specific length and bend geometry to link up with the brake pedal assembly. Other than the loop fitting, it is much different than the non-assist rod that you have.

Since your truck didn't come with a booster, the booster mounting brace was deleted from your truck as a non-essential item.

Your best bet to complete this modification would be to source the missing parts from a '69-75 rig that came from the factory with vac assist brakes. There May be some creative and safe alternatives to pursue, but those wouldn't involve cutting and welding your plunger rod. Proper length, strength and integrity of your plunger rod are vital to having a safe and functional braking system. Resist the temptation to get artsy-fartsy and take risky shortcuts here.
 
Thanx so much for the thorough/clever response!!!
I noticed the pushrod was straight, does that mean the whole set up should be straight from the pedal? As for the mounting plate....does it matter which it has? I figure since the mounting applications are opposite it will need a bit of cut and weld regardless.?
You wrote-"other than the loop fitting, it is much different than the non-assist rod that you have"
did you mean "isn't" much different"?
You also said that the creative ways wouldn't involve cutting the plunger.....any idea what those would be lol?
I anyone has pics of their original assist break mounts that would be killer!!
Thanx everyone!!:icon_mrgreen:
 
I've not attempted this modification, so I can't provide much in the way of specific direction. That's primarily why I suggested sourcing the correct parts from a suitable donor. I know it is often easier said than done. By suitable, I mean a full size IH pickup, t-all or t-ette etc. The Scout is a smaller and lighter vehicle with different braking hardware and wouldn't be a suitable donor.

When speaking of the rod differences, I meant it just as I said it. Both rods have loop or ring ends for attaching to the brake pedal. That's where the similarities end. The non boosted rod you have is straight. The boosted rod that you need is bent. IHPA does sell a universal, adjustable length plunger rod with a hiem joint fitting that might get you closer, but I don't know if that piece alone will solve the geometry and alignment issue between the brake pedal and the booster. You might contact one of the IHPA guys during normal business hours to pick their brains.

Have you heard of hydro-boost brakes? If you really want that pile to stop on a dime and give you two bits change, you should look into that topic. It might prove easier and more effective than trying to reinvent the wheel for a marginal gain.

Is this trailer you plan to pull equipped with some type of braking system? I would think that would be a must have also.
 
You must log in or register to reply here.
Back
Top