im putting discs all around my bug what master should i use?

kuleinc · Post by **kuleinc** » Wed Mar 25, 2009 2:14 pm

I put a new stock 1973 superbeetle MC in my car, and I put front wheel cylinders on the back, and dual piston calipers on the front, and the pedal goes to an inch above the floor, at this point the front wheels lock up, and at no point do the rear brakes work at all...

Suggestions?

Will this Mercedes Benz mast cylinder help?

Bruce2 · Post by **Bruce2** » Wed Mar 25, 2009 10:31 pm

kuleinc wrote:, , and dual piston calipers on the front, ?

Exactly what calipers are these? Are they stock Karmann Ghia/Type 3 calipers?

kuleinc · Post by **kuleinc** » Thu Mar 26, 2009 9:36 am

no, they are from moore parts...

http://www.mooreparts.com/store/categor ... -4-Lug-VW/

They didn't come with caliper bolts, do you guys think grade 8 bolts will be ok? and by "ok" I mean safe...

Derrick from NC · Post by **Derrick from NC** » Thu Mar 26, 2009 2:05 pm

Does anyone know what year/model Mercedes the 23mm mc that is a direct bolt-on for a beetle? Perhaps a part #?

kuleinc · Post by **kuleinc** » Thu Mar 26, 2009 2:07 pm

I'm working on a bit of a custom M/C this weekend, its an inch, the stock one is 3/4 inch. My problem is my M/C is WAY too small, and I think this should clear it up. This master cylinder would be an alternative to the pricey Porsche 944 one, that needs an adapter plate anyways.

I'll keep you posted as I get it nearer to completion and try it out in my car. Road test may not happen until early next week though, got some machine work to do...

Bruce2 · Post by **Bruce2** » Fri Mar 27, 2009 12:18 am

kuleinc wrote:no, they are from moore parts...

http://www.mooreparts.com/store/categor ... -4-Lug-VW/.

That kit has a stock Karmann Ghia caliper.
The problem you have is nothing to do with the size of the MC. There have been literally tens of thousands of cars built with what you have and there are no problems. You can try to cover up the real problem with a big MC, or keep trying to figure out the real problem.
The big problem with using a big MC is that your pedal effort goes way up.

Use bolts with grade 10.9, nothing less.

Stripped66 · Post by **Stripped66** » Fri Mar 27, 2009 9:10 am

Bruce2 wrote: Use bolts with grade 10.9, nothing less.

There may be some differences in the exact alloy, but Metric class 10.9 bolts are the same strength as SAE Grade 8 bolts.

kuleinc · Post by **kuleinc** » Fri Mar 27, 2009 11:04 am

Thats what I thought, and I'm using SAE grade 8 bolts...

As to my pedal problem, is it a bad master then?

turbobaja · Post by **turbobaja** » Fri Mar 27, 2009 11:29 am

kuleinc wrote:As to my pedal problem, is it a bad master then?

Have you had a chance to check that boot for fluid?

kuleinc · Post by **kuleinc** » Fri Mar 27, 2009 12:05 pm

I took the master out last night, no fluid in the boot... Not sure what is letting the pedal go to the floor before the front brakes lockup, the rears never engage, and the handbrake doesn't work at all no matter how tight I make the cables...

turbobaja · Post by **turbobaja** » Fri Mar 27, 2009 12:22 pm

kuleinc wrote:I took the master out last night, no fluid in the boot... Not sure what is letting the pedal go to the floor before the front brakes lockup, the rears never engage, and the handbrake doesn't work at all no matter how tight I make the cables...

What??

So the rear brake shoes don't grab the drums even with the park handle being applied? Sounds like there's your problem. Something aint right back there. What's with the front wheel cylinders being installed on the rear brakes you mentioned earlier? I'm not familiar with this type of.....modification.

I'd get those back brakes off and start double checking stuff. Lay the shoes in the drums and see how they match up to the contour of the inside of the drum wear surface. You've got to have something funny going on with those back brakes.

Post some pics of the rear brakes once you've got the drums off and maybe we can figure something out from there.

kuleinc · Post by **kuleinc** » Fri Mar 27, 2009 12:37 pm

Just so you know, this isn't the first time I've done brakes, drum or otherwise.

The rear brakes were done late at night so maybe I brain farted on hooking the cables up to the arms there or something, but before I started I do know that only one side was working, so the cables may be stretched out...

The shoes are VERY near the drums. Using front W/C's in the back is supposed to help make them work better, but I can put the rear ones back in...

It was mentioned in this thread I think...

kuleinc · Post by **kuleinc** » Fri Mar 27, 2009 12:38 pm

One other thing, the front brakes only work when the pedal is near the floor, and then suddenly lock up, I think the seals inside the master may have flipped over? At any rate the master is out now and I'll exchange it, bleed the new one, put it in, double check under the rear drums, and bleed and see how it goes...

Bruce2 · Post by **Bruce2** » Fri Mar 27, 2009 8:38 pm

kuleinc wrote:Thats what I thought, and I'm using SAE grade 8 bolts...

There is no such thing as an SAE grade 8 metric bolt. They are inch only.

Stripped66 · Post by **Stripped66** » Sat Mar 28, 2009 6:21 am

Bruce2 wrote:
kuleinc wrote:Thats what I thought, and I'm using SAE grade 8 bolts...
There is no such thing as an SAE grade 8 metric bolt. They are inch only.

True, but there is a better than good chance that whoever he got the bolts from may have simply referred to the class 10.9 bolts as grade 8 to otherwise not confuse somebody who may already be having a hard time trying to weigh the differences between US and ISO nomenclatures.

Kuleinc,
If those fasteners are stamped with 8.8 or 88, those are not equivalent to grade 8 bolts; those are the metric equivalent of grade 5.