Disc brake conversion - power booster help

[ray230]

Greetings. I've searched every post about brake conversions and cannot find help for the problem that I have.

My '68 was an original power drum car. I installed the SSBC disc conversion. Everything went fine with that install. But then I found out that my booster was bad. I had a master cylinder leak a couple of years ago and it probably got into the bladder.

My car isn't an RT and the engine is not original either ('73 400, mild cam, intake, headers), so I decided to replace the booster with a disc unit from Auto Zone that was supposed to fit. The problem is the base around the linkage is about 1/8" larger and it will not fit unless I bore the hole in the mounting plate and firewall. I'm not sure I want to do that.

Has anyone else had this problem? How did you get around it? 

I would just put a drum booster back on it but will it be enough?

I'm done rambling. That for your help.

[Rolling_Thunder]

as far as i know a booster is a booster...    disc or drum does not matter...     but I have been wrong before...     years ago...      about something....     

[ray230]

The disc booster is about 2" deeper and has a dual diaphragm.

[Just 6T9 CHGR]

Wow...funny you say that you cant mount the booster to the firewall....this guy was going through the same thing.

http://www.dodgecharger.com/forum/index.php/topic,53508.0.html

I wonder where they are getting the cores from....any chance you can post up a few pics of the one you got?

[ray230]

The one I bought was the bendix and looks just like the pictures in the link. One thing you can't see is the base under the linkage boot. My original does not have a base coming up from the housing. The new one does and that is what requires the larger opening.

[Just 6T9 CHGR]

The one I bought was the bendix and looks just like the pictures in the link. One thing you can't see is the base under the linkage boot. My original does not have a base coming up from the housing. The new one does and that is what requires the larger opening.

Would love to see a pic of this....

[ray230]

Here is a picture.

[Just 6T9 CHGR]

Hmmm...I wonder what the back half of that booster was orig from?

The correct back should look like this and if I remember correctly, only has a small lip like the one you pictured on the right.

Are these supposed to be "New" boosters or rebuilt units?  What's it say on the box?

[ray230]

The "new" is a rebuild. I assume that they use cores from a range of years that are supposed to be interchangeable. But not in this case!

They ordered a drum booster today. I'll pick up Friday and see what it looks like. The thing is I don't know if the extra capacity of the disc unit is the better choice or if the drum unit will work fine?

[Corellian Corvette]

The booster you have is not the same one as in the pictures. It looks similar but it is not - the cardone ones you get now are not correct and they don't fit (just as you discovered) I had exactly the same problem, and now have exactly the same booster lying in my garage...

The only thing you can do is try and track down an original Bendix and have it rebuilt.

I was advised against the drum booster for disc applications as a disc brake car requires more line pressure. Not sure you'll get a good boosted feel, but worth a try I suppose!

[ray230]

Where did you find the correct disc booster?

[Corellian Corvette]

I had to search around on ebay, moparts, and here. Post in the WANTED section here and on moparts - they come up every now and again...

[69chargerboy]

Where did you find the correct disc booster?

Hi ray230, Is this what your looking for? I bought mine from this guy, THERAMMAN!

http://cgi.ebay.com/ebaymotors/BENDIX-BOOSTER-FOR-66-70-POWER-DISC-BRAKES-B-BODY_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318Q7c301Q3a1Q7c293Q3a2Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem220380475776QQitemZ220380475776QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

[Corellian Corvette]

That is exactly the correct unit, but it does not appear to have the correct pushrod for non-hemi cars. IIRC, hemi boosters had a bracket that moved the booster up a bit to clear the valve covers - for 440/383/318 cars, the booster is mounted directly to the firewall and I think that is not the correct pushrod. I would ask the seller if he can replace the pushrod for your application (if he's a rebuilder, he should be able to)

[ray230]

Thanks. I pulled up the link and called the number. He said this is the exact one that I am looking for. I am going to call him back tonight for details. His ebay listing is $250 or best offer. What did you pay?

Thanks again!

[Corellian Corvette]

I'm not 100% convinced that rod length is correct. It looks too long.

$250 (assuming it's rebuilt) is about right. Seems fair, (assume that's $100 for the booster and $150 for the rebuild) is not out of line considering rarity.

[Just 6T9 CHGR]

I'm not 100% convinced that rod length is correct. It looks too long.

$250 (assuming it's rebuilt) is about right. Seems fair, (assume that's $100 for the booster and $150 for the rebuild) is not out of line considering rarity.

Looks right to me....the fact that the dust boot is off might be deceiving

[ray230]

Thanks for both of your help. Reading your posts you have been through this already. A job I thought I would get through in an afternoon keeps growing.

I plan to ask for rod measurements, etc. when he calls back.

I'm a little nervous about someone that is so far away and I don't have a clue about. How was your transaction 69chargerboy?

[ray230]

I went by Auto Zone to look at the drum booster they ordered. Firewall side looked and measured correct. The MC side looked a little different. I decided to let them keep it. They also took back the disc booster that wouldn't fit. I guess I got lucky there.

I just ordered one from theramman. Should ship tomorrow or Monday. I'll keep you posted on how it goes.

[jar1292]

 im in need of converting my 70 yet I have no idea on where to begin on looking for information, can you help me out alittle. i hate doing foot work! i would rather just have somebody tell me what I need to put in! any info would be greatful thanks

[chargerguy111]

ray230,Im the other guy notjust6t9CHGR spoke of on here with the same problem you have.You explained it better than me.Icouldn't send pics because I couldn't find my download cord to my camera.I went through 2 boosters at NAPA and 1 at Autozone.All 3 were identical.I spoke with a man that restores old mopars and he says you cannot,in his experience,buy these new at parts stores.Im going the same route you did by ordering a drum booster at Autozone,which you said you did.Did it not look like it would work?I haven't picked mine up yet.

[ray230]

chargerguy 111

THe Auto Zone drum booster may have fit. The firewall side looked and measured ok, the booster side looked different but may have worked, I didn't try it. My concern was the amount of boost. I read and been told that it wouldn't be enough for discs. But I have heard some that have used drum boosters with a front conversion and were happy. I've ordered a disc booster from theramman. Let me know how it works out for you.

[chargerguy111]

How much are you having to give for one at Theramman?I may go that route also.

[ray230]

$270 incl shipping. Should arrive Wed.

[ACUDANUT]

 I think I can do better than that (price wise) And I have everything you need. Spindles, rotors, disk brakes, calipers ,proporting valve and booster. I will take 250.00 for all.  Do not worry moderators, I will post pic's on the correct site.