Brake Booster swap

[Dave Baro]

Hi,
I'm new to the Forum and this is my first post. I have a 66 300 coupe.

Can I swap my Midland Ross power brake booster (which has failed) with a Kelsey Hayes Booster? I can find a KH rebuilt booster but can't find a MR rebuild.

Thanks

 

[Ross Wooldridge]

Can you post pics of your booster?

I assume your car has drum brakes - I believe both boosters were for drum systems, as the factory disc systems had Bendix boosters. However I don't know if the two drum boosters were interchangeable.

Your other option is to have someone rebuild your existing booster - then you know it's right.

 

[Zymurgy]

FYI if you haven't gone to a dual master, this might be a good opportunity to do it. You can get a 67 booster and master for $130 at O'Reilly's. I did this 4 year ago and was very happy. You would need to get a new distribution block too.

 

[Zymurgy]

This is a good source for the distribution block, if you choose to go that route. Inline Tube - The brake plumbing experts

 

[Dave Baro]

Ross: Here are the pictures of the two boosters. Interestingly, both are covered in the service manual. Zymurgy: I'm definitely going to go to a dual brake system with discs in the front (because I really like driving this thing).

 

[Ross Wooldridge]

Hi Dave,

Both the boosters you pictured are for drum brakes and should be interchangeable as far as I know.. I am surprised you can't find a rebuilt one that's the same as your original as they were/are extremely plentiful. There are ones on eBay right now.

Power Brake Booster-Vacuum w/o Master Cylinder Cardone 54-73520 Reman | eBay

Please note: If you are going to upgrade to front discs, the two boosters you pictured are not suitable and while they'll bolt up and work they don't provide enough boost and will let you down at the worst possible time. Don't let anyone (disc kit supplier or enthusiast) tell you otherwise. There are threads on this forum that detail the correct and safe way to do a disc upgrade.

There is a specific booster for disc systems which you must use. C body cars use an 8.75" Bendix dual diaphragm booster. They are hard but not impossible to find. B body ones look almost identical and I believe bolt up but I don't think they're suitable either or Mopar wouldn't have made the larger booster for our cars.

For reference here's a link to the smaller B body disc booster:

1966-1969 Mopar B Body 8 Inch Dual Bendix Brake Booster | eBay

 

[Dave Baro]

Ross,
Thanks for saving me a bunch of time and money. I'll send that one back and just wait until I switch to discs and change the whole setup.
Dave

 

[Zymurgy]

Ross is the man, he helped me out bunch with my brakes. Great information from him.

 

[saylor]

" Whenever possible and where space allows, it is recommended that you use the largest single-diaphragm unit, as these perform better at lower vacuum pressures. "

- Hemmings Muscle Machines 'Power Brake Boosters' Dec. 2008

 

[Ross Wooldridge]

While Saylor's info is valid, keep in mind that if your car is column shift you will experience interference with the shift linkage if you use a larger than factory booster.

 

[Dave Baro]

Thanks again all for great Help!
It’s been a year now and the booster has been replaced with the KH and dual master cylinder. (A few other parts included 2” drop spindles, wilwood 11’ disc brakes and a tubular upper control arms). I kept the stock front end settings and it stops and drives beautifully. Kept all the parts in case I want to return to stock.

 

[Samplingman]

Thanks again all for great Help!
It’s been a year now and the booster has been replaced with the KH and dual master cylinder. (A few other parts included 2” drop spindles, wilwood 11’ disc brakes and a tubular upper control arms). I kept the stock front end settings and it stops and drives beautifully. Kept all the parts in case I want to return to stock.
View attachment 191050

Please post more pics of this beauty!!

 

[mopar_4life]

Thanks again all for great Help!
It’s been a year now and the booster has been replaced with the KH and dual master cylinder. (A few other parts included 2” drop spindles, wilwood 11’ disc brakes and a tubular upper control arms). I kept the stock front end settings and it stops and drives beautifully. Kept all the parts in case I want to return to stock.
View attachment 191050

Car looks great. Where did you get the drop spindles?

 

[Dave Baro]

Here’s a few more shots of the car. Spindles came from Magnum Force (MFR19200 Mopar A,B,E,F,J).
If you like, I can give the rundown and pn’s for the stuff that was required to put those in. Different lower ball joints with a taper bushing adapter. The stance looks OK but I believe I might have missed on the tire sidewall height. Next set might be a little taller. By the way, my speedo just gave up the gun. Does anyone have any “gotcha’s” taking that thing out?

 

[Ross Wooldridge]

Beautiful car.

Speedo removal with the steering column in the car is a PITA... take the column out (not hard to do) it is WAY easier then.

 

[Dave Baro]

Thanks Ross.

 

[Ross Wooldridge]

To reduce stress on the column's rubber coupling at the firewall, drive the roll pin out by the pot coupler at the steering box first, unclip the wires for the turn signals, unbolt the floor plate, then LASTLY undo the yoke mount under the speedo. Watch the headliner as you lift the column up and out.

 

[Dave Baro]

Ok. I’m on it. I’ll let you know how that goes.

 

[Dave Baro]

Ross, BTW I haven’t discounted your comments on the brake booster diaphragm. So far, my Frankendisc setup is working with the KH Booster, a dual master cylinder from a Ram truck (I know...) and the Wilwood 11” four piston. Had to lean into the new system a few times and was happy with the results.