[Unkie]

Hi,

The master cylinder on my Austin A40 sometimes empties out the rear reservoir. This only happens when the car is sitting still --- not when I'm driving.

It doesn't seem to be caused by heat, even though the MC is very close to the exhaust (it's under the car), and it doesn't seem to have anything to do with how much driving I've done before it leaks. Sometimes I can go a good distance and there will be no leaking and another time I can drive around the block and find a puddle under the car a half hour later. Always from the rear reservoir.

So I'm replacing the MC.

I took the MC off the '87 Suburban that I used as a donor car for the engine and transmission for my '57 Chevy. This was a power brake setup and I want to know if I can use the MC from the Suburban on the Austin with no booster.

From what I can see of the Austin MC, it looks almost identical to the Suburban MC. Can I use a MC that was in a power brake car with no power brakes and what else do I have to look for to see if the Suburban MC will interchange with the MC that's on the Austin?

I don't know what the MC in the Austin came from originally and if I have to, I'll take it out and try to get a part number off it and get the same one, but I'd like to try to use the MC from the Suburban if I can, since I already have it.

Thanks!

[cobalt327]

First, I know squat squared about your Austin A40.

What you should consider w/such a swap is the ratio between the slave cylinder size compared to the master cyl. size. This affects pedal travel and effort.

The 'burb has disc fronts and is (obviously) a large, heavy vehicle. Whether you can get a satisfactory performance from its m/c on your Austin remains to be seen, but start with comparing the bore sizes between the two masters.

[Unkie]

The Austin has an MG V8 front suspension with discs and an Olds/Pontiac rear with discs. If that helps.

[cobalt327]

Originally Posted by Unkie

The Austin has an MG V8 front suspension with discs and an Olds/Pontiac rear with discs. If that helps.

???

Dude, that quit being an Austin a long time ago, by the sounds of it!

But seriously, why don't you rebuild the existing m/cyl?

With the bore diameter being known, even if a "kit" doesn't exist for your exact m/c, you can get the correct size seals for it. If the pistons and bore isn't too far gone, it's a simple matter of hone and replace the seals and dust caps.

[Unkie]

That's always a possibility.

I'm not ruling out rebuilding the existing one.

A picture of the car. So we all know what we're dealing with....

[cobalt327]

If it goes anything like it looks, you had better have some good brakes!

When you say "Austin" I think, well, Austin. As in one liter, 4 cylinder grocery grabber.

That looks like a race car w/an Austin body- a big difference.

BTW, it's been a while since I've heard of anyone using the old, bullet-proof early Olds/Pont. 3rd. member. Is this an old build, updated or a new build-up? What engine, trans, etc.

Come on, DETAILS!!!

[Unkie]

It's a rebuilt old build.

Here's some details taken from my YouTube account, which is here: http://www.youtube.com/user/AlteredAustin

The engine is a 355" Cbevy 4 bolt main block with a steel crank, 12.5:1 compression, unknown cam , old double hump heads with stock size valves with roller rockers, Demon Mighty Demon 650 Carb on a Weiand Single Plane Manifold, Summit HEI Distributor, 8 quart oil pan, S&S chrome headers and Summit glasspack mufflers.

Horsepower is approximately 400.

The transmission is a full manual Hurst shifted Turbo 400 with about a 2000 RPM stall speed converter and a B&M deep pan, Olds/Pontiac with 5.56 gears and a spool or welded gears, I'm not sure which and disc brakes.

The wiring is an American Autowire Highway 15 kit.

Front Tires are Pro Trac front runners and the rear tires are Pro-Trac also, both from Coker Tires.

The car weighs approximately 2000 pounds. The engine is set back where the front seat would normally be, so you drive from the back seat. The car is all steel, including the hoodscoop. The doors, hood and trunklid are skins only. There are no internal structures.

The chassis is the original Austin chassis from the B pillar back and from the B pillar forward is a professionally built 2x3 frame with a slightly extended wheelbase. The rear suspension is the original leaf spring with Air Ride air bags.

The front suspension is an MG V8 rack and pinion.

When the car was raced it was a consistent 10 second flat car.

[cobalt327]

Thanks for the run-down. I can only imagine how much fun that ride would be, especially w/5.56's!!!

Many years ago, my Dad and future bro-in-law (who was the "gofer") built a '40's Ford Anglia w/a 354 Fire Power, A/T and same rear as yours.

It, too, had the engine set way back- it was driven from the back seat!

The "drive shaft" was basically two CV-type u-joints welded together, which was the Achilles heel of the drive train because of the harmonics that were induced.

But while the joints lasted, it was a Beast!

[Unkie]

Yeah, the driveshaft on the Austin is about 7" long.

It is fun to drive. You can't see traffic lights. I watch the walk/don't walk signs. It rides like a tank - it's really bad (I mean really bad), but I'm working on that.

But besides those things, I love it. I've never had a car that got more attention.

It also sets off car alarms even just idling down the street. Which is also fun. I think it's actually gotten worse. I had it out for the first time this year over the weekend and alarms were going off all over the place. I think the glasspacks are burning out.

[tommer2]

That's one cool rod!!! That's like Jegs famous first gasser!!!

[Unkie]

Thanks....