Disc brake booster question

[Muswagon]

Hey there. I am having brake issues on my 68 Roadrunner. First, the backround story;

- Car was factory power drum. Old stuff was worse than junk, bought SSBC front disc conv kit

- Had NO brakes at all, new booster, still no, turns out master cyl from bunk in box from SSBC

- No brakes now due to no vacuum, 78 440, guy that built has stupid cam, for now went with vacuum pump....'some' brakes. Pump pulls 19 inches ish

- The last hurdle now is that I am 99.9% sure even though I ordered the booster for power disc, they gave me power drum...in fact make that 100% sure

My question is, with good vacuum, new master cyl, new front kit, properly bench bled and properly wheel bled, will having a single diaphragm booster for drum cause poor assist with front discs? I believe the calipers are the Mustang Kelsey Hays style, as replacement pads are 67 Mustang I think the manual said.

When I stand on it, and the boost is over, the brakes will lock, and there is alot of fluid pressue when we crack the caliper bleeder to check.

Will a dual diaphragm booster be my saviour? And from the looks of it, this is the one I need; http://napaonline.com/Catalog/CatalogItemDetail.aspx?R=NBB5473603_0332947700

 

[Muswagon]

I have also seriously considered this setup;

http://www.performanceonline.com/19...R-PLYMOUTH-CAR-POWER-BRAKE-BOOSTER-KIT-19530/

 

[Propwash]

You need a Disc Brake booster.......The power assist ratio between a drum vs. disc booster is different. That is the booster you need in the 1st link. It is Bendix. If you can snag that bendix for that price and they do in fact have one in stock, grab it!!!! Those are seriously hard to find and typically go for $400-800 rebuilt on ebay. That package in your second link would be useless for you. Problem is every Tom Dick and Harry are selling that same exact kit but they slap their name on it. It is specifically made for a MANUAL brake to power disc conversion. Not for power drum to power disc. Do not buy it. It will not work without some serious mod's to your car. Pretty sad none of these criminals mention that fact when they sell these cheap chinese kits.

The linkage off your old power drum booster to the pedal will bolt right up to the Bendix Booster.

A few other things you will need....A proportioning valve. Found at places like year One, Classic industries and others. or go with a Wilwood adjustable.

A disc/drum Master Cylinder with built in residual vavle. Rock auto sells the bolt on OEM style Bendix style. Not too pricey.

http://my.cardone.com/English/club/members/customer/ecat_brands/imageinfo.asp?PARTNUM=101475

Another piece you will need is the bendix booster plate:

http://www.megapartsusa.com/proddetail.asp?prod=102%2DBB4

Get this stuff and you'll be set....Myself I would also double verify you have the proper amount of vacuum to the booster. If not, a vacuum can or Electric Vacuum pump may be your only option with a large cam.

Good Luck.

 

[Muswagon]

Appreciate the feedback. That is the Master Cylinder I found. The Bendix dual diaphragm booster is in stock in Canada, and I also found it at a few stores in the USA, going to order it today along with that plate.

I figured that on the kit based on some other threads when I searched, thanks for the feedback and warning.

I have a proportioning valve already from SSBC kit.

Thanks again!

 

[Propwash]

No problem Muswagon. Glad to help another mopar guy out. Good luck moving forward with the rest of your brake project.

 

[Muswagon]

I'm really curious to see what they send me. I ordered it today. Napa Canada is a huge premium over Napa USA, cost $163 in Canada. Still, if its the real deal then yee haw. I can't see how though, everyone is saying they don't exist as there are no cores. Should have it Monday, I will post some pics.

 

[Propwash]

Don't quote me on this but now that you mention it, I breifly remember reading somewhere that the NAPA brand ones look pretty similar but are not exact to the OEM Bendix. I couldn't tell you if that was 100% true or not, but you saying that sparked a memory. The Bendix due exist though. I found one through one of those genaric online auto parts stores. Luck of the draw I guess. Took about 6 hours of surfing to find one.

Or you could empty your spare pocket change and pick this one up on ebay.

http://www.ebay.com/itm/MOPAR-HEMI-DODGE-POWER-BRAKE-BOOSTER-DISC-VACUUME-/390331362159?pt=Vintage_Car_Truck_Parts_Accessories&vxp=mtr&hash=item5ae18feb6f

 

[generaljmwlee]

does anyone repop the linkage for those I have the booster just not the linkage

 

[Muswagon]

Don't quote me on this but now that you mention it, I breifly remember reading somewhere that the NAPA brand ones look pretty similar but are not exact to the OEM Bendix. I couldn't tell you if that was 100% true or not, but you saying that sparked a memory. The Bendix due exist though. I found one through one of those genaric online auto parts stores. Luck of the draw I guess. Took about 6 hours of surfing to find one.

Or you could empty your spare pocket change and pick this one up on ebay.

http://www.ebay.com/itm/MOPAR-HEMI-DODGE-POWER-BRAKE-BOOSTER-DISC-VACUUME-/390331362159?pt=Vintage_Car_Truck_Parts_Accessories&vxp=mtr&hash=item5ae18feb6f

Its written carefully in the Napa listing, as OE mfg is Bendix...so, could mean either its a real Bendix or like you said, looks close to one, either way I will be money ahead if its the real deal.

 

[Propwash]

does anyone repop the linkage for those I have the booster just not the linkage

Myself I haven't seen anyone selling them General. It's not like the linkage is that rare (on both drum-Disc cars), just the disc booster itself is. Post a wanted ad here or check ebay. Maybe something will shake loose for ya.


I'd be interested to find out if that is in fact a Bendix Muswagon. The picture in the NAPA link sure does look like the Bendix I have. It has the proper part# as well

http://my.cardone.com/English/club/members/customer/ecat_brands/imageinfo.asp?PARTNUM=5473603

 

[Muswagon]

The other option I think is to order the C body one (5473600) which seems to have more stock online, and order the correct rod from that really angry brake guy on ebay. I pick it up Monday, I will post pics. Christmas came early if its the right piece. I don't care what it looks like, if it bolts up, is dual diaphragm, and has correct rod length than Bob is indeed my uncle.

 

[Muswagon]

Well, its the right one! I would have never have guessed. My advice to anyone looking for one, you just never know when a core must pop into the system?

 

[Muswagon]

I looked at the Cardone pics, mine seems a little different, but I am just looking for functionality, not looks

 

[Propwash]

Outstanding! That looks right on to me. Below is the rebuilt one from Cardone I found, even has some complimentry pitting from years of service. Looks like you scored big time. Compared to the Ram Man one on ebay, I can't tell the difference in yours. Good score Muswagon. Thanks for posting. I may go pick one up (if any more available) for my coronet down the road.

 

[Muswagon]

Now an installation question. To get the old one off, which bolts on the linkage need to come off before I can access the main one holding the rod. The four nuts are a Biotch, I remember that from 3 years ago, but my buddy had already taken the linkage apart.

 

[Muswagon]

Yo, propwash, help!

 

[Propwash]

Muswagon...You just looking on how to rip out the old booster and linkage? To take it out...yeah, the four nuts that requires turning your hand/arm into an Origami project gone bad need to come off, remove the bolt holding the multiplier arm at the pedal, then remove the the lowest bolt. Work the linkage out through the hole in the firewall. Been a while, but that's how I remember doing it. Is that what you were asking or am I off base here?

 

[Muswagon]

Yup, thanks!

 

[Muswagon]

There was nothing wrong with the booster I had. installed the new one, still not where I want it to be. so, anyone want to buy a cardone booster, not the bendix style, but does have the proper B Body rod. I will click a pic tonight.

 

[Propwash]

Interesting....Maybe SSBC wasn't pulling your chain when they said they supplied you with a Dual Diaphram booster off the bat. That's the only thing that makes sense in that department. Obviously the problem lies somewhere else.

Other things to check:
Wrong bore size in master, Oversized creates a hard pedal, undersized the opposite.
No residual valve in master, spongy, poor brakes
Failing Residual valve in master, causes lock up after a few pumps due to fluid not being allowed back in the master
Collapsing rubber lines...poor or no braking.
Bad Master..Spongy pedal that will sink slowly to the floor

Heres a bit wilwood sent me years back working on an Fairlane with similar issues:

http://wilwood.com/TechTip/TechTroubleshooting.aspx