Bigger master cylinder problems

haasad · haasad's Garage

Only my second post so be gentle.

I'm reassembling my r inspired hot rod and have hit a snag. I have a 75 european "S" as my base car. I have fitted an alloy crossmember and associated brackets to save weight. Tonite I tried to fit my 23mm brake master cylinder and it just fouls the crossmember I can get over this with a little milling at no risk but there is no chance of the steering rack clearing it unless it is fitted upside down!Unless it can tolerate being upside down ie with the reservoir feeds entering from underneath ( which I think would cause problems with bleeding) what are my options ? has anyone else had this problem?

keep the faith

andy

Bill Verburg · Bill Verburg's Garage

It's tight but it does fit

911pcars · 09-26-2007, 10:37 AM

The MC reservoir inlets should be on top to allow air bubbles to escape. However, I suppose it's possible to purge trapped MC air into the calipers. But why make the bleed path more tortuous?

Sherwood

haasad · haasad's Garage

Bill thanks quick reply! my cylinder doesa look identical to yours but "handed" the opposite way. Do you by any chance have a mounting flange to end of cylider dimension ?

andy

Bill Verburg · Bill Verburg's Garage

ATE made 2 m/c that were the same except for chirality one is right handed and the other left.

You need the other one. It's best to buy a kit that includes the angled fitting for the forward feed and the actuating rod which will have the correct length. The stock rod won't work

haasad · haasad's Garage

Bill, thanks for the help. My cylinder actually fouls the rack gear. No chance of it gaining clearance right or left haded is your rack on bump steer spacers or pehaps my crossmember is somehow in a different position although it looks identical to yours only right hand drive. I already have the angled reservoir feeds and longer actuating rod. Only fix I can see short of mounting it upside down is to machine a wedge spacer to go against the bulhead where the pedal box bolts come through. Too much hassle to think about right now!!!

911pcars · 09-26-2007, 11:40 AM

"Do you by any chance have a mounting flange to end of cylider dimension ?"

and/or...... how much space is there between the bulkhead and the aluminum crossmember?

I'd like to know as well.

Sherwood

DUK · 09-26-2007, 11:57 AM

I had to install the bumpsteer spacers for the rack to help clear the 23mm master. Just my .02

Bill Verburg · Bill Verburg's Garage

I'll have to do some digging to see if I have the spec on that. In the meantime here is a pic of both the 23 and 19

As I said, it is tight but it does fit

Bill Verburg · Bill Verburg's Garage

I installed the bumpsteer rack spacers as well, but I don't recall them being necessary

DUK · 09-26-2007, 12:05 PM

On mine the rack spacers helped the inlet hose to relax and not get into the bellows so hard.

klaucke · 09-26-2007, 02:05 PM

Perhaps it is worth mentioning that Andy (user Haasad) is in England, so his car is likely RHD. Perhaps this requires the other enantiomer of MC? Although looking at Bill's picture, it seems that it the MC depicted would also work w/ a RHD application, because the lines could go straight to the tunnel instead of looping over the MC.

vash · vash's Garage

andy, i had to do this too. friend's car.

it takes two people. you need to loosen the entire pedal cluster, and get the welded bolts that go thru the firewall (holds the MC) into the car, and out of the way. then have someone hold the MC up, and then jab the stud back thru the holes and into the MC. plenty of room if you do this. also, have the plunger shaft from the brake pedal ready. push that into place while all the components are loose. if not, you will find that the sleeve that surrounds the shaft hole on the MC is longer that the stock unit. there isnt enough room to lift the shaft into place. so install it at the same time. good luck.

easypeasy.

cliff

911pcars · 09-26-2007, 04:14 PM

I posted this alternate MC about a month ago. Not sure it would be a suitable replacement, but it seems like it could work. It's 22.2mm for VW Corrado. The factory MC is 19mm and the big brake MB master cylinder is 23mm. I assume the mirrored outlet ports are for LH and RHD applications. That might make it easier to fabricate brake lines. Comments?

Sherwood

haasad · haasad's Garage

Thanks guys. Klauke yes my car is Right Hand Steer. My cylinder is exactly as Bills but the opposite hand. The push rod is the correct length. I will have another go at fitting tonite and try to post a picture that illustrates the problem.
It could be I need to drop the cross member again to get it in .

keep the faith

andy

haasad · haasad's Garage

Lets try the photo attach and see if it sheds any light?

vash · vash's Garage

yup, read my post. exact same situation. do what i suggest, it will pop right in.

haasad · haasad's Garage

Just tried. Even bolted it all up, still too tight to rack. I think a previous heavy accident could have "re aligned" the floor to crossmember height. I'm going to try the Corrado option. I'll keep you informed.

PS easy to upload photos here. You guys across the pond could be first to see the result of five years hard labour at the shrine of Porsche!

JP911 · JP911's Garage

Interesting challenge. The crossmember is close with the 23mm MC, but I've never heard of the steering rack being in the way. If you look at the first pic that Bill posted it looks as if the MC is angled down slightly, but in your pic the MC looks to be parallel to the floor pan. I wonder if this is part of the problem? Not sure exactly how you would solve it though.

haasad · haasad's Garage

Jon, Hi.

you are absolutely right with your observation. Even bump steer spacers don't give me enough room. I'm off to my parts shop to dig through their master cylinder stock!

andy