66 Coronet, Power Brake Booster, Spacer

[SassyPants]

Hi Folks, I was "admiring" my work on getting the brakes bled on the car (we still have work to do in that department, grrr). I went back to look at the old pics and noticed that I have a slightly different Brake Booster now than was on the car before. So, the question.

The old Booster had a "Spacer" between the booster and the Master Cylinder. It is in two parts, one Alum and the other plastic, (you can see that spacer better in the "New" pic). Just wondering if that spacer is supposed to stay on the car with the "New" booster or if the Master Cylinder is meant to be bolted directly to the Booster in the new application? Here are some pics. Thanks, B.

 

[Ernie ingling]

Found this shows a plate like yours

 

[R/T Boy 67]

Make sure that the piston rod sticking out of the booster is not pushing on the master cyl. piston when at rest. You will need to measure carefully. The rod should be adjustable.

 

[SassyPants]

Make sure that the piston rod sticking out of the booster is not pushing on the master cyl. piston when at rest. You will need to measure carefully. The rod should be adjustable.

R/T, thank you. If it is "pushing" on the Master Cylinder piston, what does that cause? Thanks, B.

 

[dan juhasz]

R/T, thank you. If it is "pushing" on the Master Cylinder piston, what does that cause? Thanks, B.

brakes that won't release

 

[Ron H]

My setup doesn't have a spacer and don't see a specific reason for one unless some systems had for dimensional specs there is no necessary 'seal' here to my knowledge other than maybe dirt/contamination. A vital issue is the booster rod to MC tolerance which a spacer or not would alter. The gap clearance varies from one mfg to the other; but a little gap is necessary I think OEM spec for mopar installs was around .910. I have some issues with my disk conversion and one of them may be this spacing so I'm waiting for the rod gauge I ordered - it is 'H' shaped with a an adjustable rod through the center of it for an easy method of checking this. You will find them under a web search for booster rod gauge. There are cheepies on eBay for around 12 bucks; better ones are about double this price. You could also measure with a depth mic

 

[R/T Boy 67]

There is a port just in front of the piston that enters into the reservoir. If the piston is pushed forward just a little at rest it covers this port and removes the reservoir from the system. Any pressure in the system can't be relieved, and any fluid loss can not be made up. You would not be able to bleed the system properly.

 

[RussT Plymouths]

The "spacer " you have is a part of the original power booster. It's the air filter assy. (see photo).

If the new booster needs something like it, it may be a different style and that's something to research. What manufacturer is the new booster?

 

[SassyPants]

OK guys, I think I have it figured out. In the FSM it shows that there were three Power Brake Boosters used in 1966 on the Dart/Coronet cars. The one this car came with originally was the Midland Ross unit. It is on pages 5-19 of the service manual. That one requires and uses that "spacer" which is actually the air Filter Cover and Filter for the front of the unit. When I traded that one in, I was not paying enough attention to what I had with the comparison. I got back a rebuilt Kelsey-Hayes unit. It does NOT use the front spacer/filter. Instead it has an "air cleaner plate" on the font between the booster and the Master Cylinder which looks to be more of a Gasket, though probably not gasket material (my bet is it will be a steel gasket?) That explanation and how tos are on pages 5-27 and 5-28 of the FSM, if yours is like mine. The unit I got did not come with that "air cleaner plate", so I will have to figure out Plan B on that (figure 3, page 5-28). If anyone has any ideas where a feller can find one of these air cleaner plates, please let me know. The other unit that was used in 66 came from Bendix which is on pages 5-24 on the FSM. The Bendix procedure carefully goes through how to set the Master Cylinder Push Rod, as described in previous notes.

If you looking at your Booster, here is how you tell them apart on visual exam. The Midland Ross unit has "Clamp Band" that holds the Front and Back portions of the Cover Assembly/Housing Assembly together. The clamp band is secured by a screw and nut on the Band that is very visible. As well, it will have that easy to see "spacer/Filter Cover" on the front between the MC and the Booster. The Bendix uses Bolts/screws to hold the front and back portions of the Cover/housing Assemblies together. There are 8 screws that hold it together going around the Housing Assembly. The Air Filter for the Bendix is on top in the back portion of the Booster near the fire wall. The Kelsey Hayes is held together with Friction and is called the "Housing Lock" that locks the Front cover with the Housing assembly. There are NO visible screws or bands. The Air Cleaner is rather inside the outside Cover Assembly around the Push Rod. That is what I have.

So, I have to find the Air Cleaner Plate that goes between the MC and the Booster to complete this set up on the Kelsey Hayes. If anyone has one laying around, let me know. Otherwise, I am on the hunt to find one. Thanks again to you all and best to you, B.

 

[SassyPants]

The "spacer " you have is a part of the original power booster. It's the air filter assy. (see photo).

View attachment 950356

If the new booster needs something like it, it may be a different style and that's something to research. What manufacturer is the new booster?

Russ, this is the Midland Ross Booster. This is the one on the car when we started the process. Wish I would have gotten a new/rebuild one of these, it would have made the next step easier. Best, B.

 

[SassyPants]

Here are a couple of pics of the old Midland Ross Booster. You can see the Kelsey Hayes above, so only one left to see a pic of is the Bendix. Thanks again for the help and Best to you all, B,

 

[Ron H]

Following your post kinda confused: you had the midland booster then got back a KH booster. You describe that the KH doesn't use a spacer unlike the midland? If so then why would you need to hunt down a spacer/filter for it? Maybe I'm missing something. Also curious, does your pedal linkage system use a bell crank? Reason I ask is my SSBC conversion kit using a Delco booster does not employ a bell crank (not sure if this is necessary). My kit showed a gasket btw the MC and booster and didn't come with one.

 

[SassyPants]

Ron, thank you for your questions. So, the KH booster needs only a "gasket" between the MC and the Booster, not the spacer and filter. My bet is it is a tin gasket that is needed on the KH, but I am not certain. So, I was hopeful to find someone that has rebuilt or has as a Parts Vehicle with the KH booster that would be willing to sell me the "Air Intake Plate" that works with the KH. What happened to you happened to me, when I got the KH, it did not have the Air Intake Plate. So, here I am, looking for an Air Intake Plate. Here are some Pics I just took of the Inside of car on the Pedal Assembly from side, front and then in the Engine Compartment. Hope that helps with the second part of your question?? Best, B.

 

[SassyPants]

Hi folks, here is an exploded view of the Kelsey Hayes Power Brake Booster. If you look in the upper left side, you see the Master Cylinder. Next in the exploded view is the Air Cleaner Plate. I have read all there is to read on the system in the FSM and it does not say what happens if that Air Cleaner Plate is not installed. My bet is that it hampers the air coming into the unit. It really looks to me like it is a metal "gasket" type of piece. I have been online looking for this part and so far have struck out. If anyone has any idea where I might find the Air Cleaner Plate for this Kelsey Hayes unit, I would be beholden to you. Thanks in advance, B.

 

[SassyPants]

So, update. I found the receipt for the KH rebuilt Booster. Oreilly's coming from Cardone. The part number is 54-73501 from Cardone (which is the Reman Midland Ross). Apparently, Cardone put the wrong Booster in the box when it shipped. Dum me did not check that closely when I exchanged out the "core". So, today I called around and NO Inventory at the usual suspects. So, I called Cardone and they said they have NO inventory and no longer plan to Reman the Midland Ross units, the above part number, and they wished me good luck. After doing some big shopping, I found one on Amazon from Autoplicity "only one left". So, I ordered it to arrive by May 26-28, Fingers Crossed. I decided to trade out the KH unit now in the car to get what was Originally in the car which is the one from Midland Ross, part number above. So, for those of you that have the old Midland Ross units and go online at Orielly, Advance, AutoZone and the other usual suspects, it will be a tough buy. Save your old unit and do as others have done here, get someone who can do a quality rebuild. Wish I had thought of asking for that advice earlier. You all are great and I am thankful that you all are willing to share your adventures. Best to you all, B.

 

[SassyPants]

Further Update. It is May 28 and no Midland Ross Booster from Autoplicity. I got an email from Amazon that the money will be replaced on my credit card account "customer return". Well, as you can imagine, I have not even yet seen the booster. I called Autoplicity and spoke to the folks there. They still show ONE left, but price is up a few dollars. What they said was they do have ONE, but upon inspection, it is not of good quality so their IT folks have been told to take the part out of their catalogue. So, they cancelled the order and they will send the bad unit back to Cardone. Now I am on the look for another Midland Ross unit reman from Cardone, if I can find it. OOOOOOr, does anyone know if perhaps one of your fav rebuild guys might have one?? If so can you please give me a contact so that I can give them a call? Man, wish this was not this hard. Help please. Thanks in advance, B.

 

[Demonic]

1. Where's your original booster?

2. Pack it up and send it to Booster Dewey in Oregon. He may have spares of what you need. http://boosterdeweyexchange.com/

3. Get rid of that single-reservoir MC before you're shopping for a new front clip.

 

[SassyPants]

Thank you Demonic. The original Booster went to our good friends at Oreilly's. When I ordered the Reman, I was Dumb and Dumber all at the same time and did not closely check my booster against the new one. I got a booster that was used in 66, just not the correct one. So, I do not have one to rebuild, I am sorry to say. Get your point on the Single-Res. Unless one bites me on the ....., I will give Booster Dewey a look. Thanks again. B.

 

[SassyPants]

1. Where's your original booster?

2. Pack it up and send it to Booster Dewey in Oregon. He may have spares of what you need. http://boosterdeweyexchange.com/

3. Get rid of that single-reservoir MC before you're shopping for a new front clip.

Hi Dom, what MC would work best for a replacement for this Single Reservoir unit? Then, suppose I will need a Proportioning valve so what have we found works for that chore? Finally, I would guess the "splitter" that I have just below the MC would go away? I guess, how to plumb it from MC to Fronts/Backs? Thanks in advance. B.

 

[SassyPants]

1. Where's your original booster?

2. Pack it up and send it to Booster Dewey in Oregon. He may have spares of what you need. http://boosterdeweyexchange.com/

3. Get rid of that single-reservoir MC before you're shopping for a new front clip.

Dem, thank you for your coaching. Look what the Delivery Man brought today.

Just one more piece to the puzzle and we will be ready to once again do the Bleed the Brakes dance on SP. Best to you all, B.