Brake Booster Vacuum Pressure

[Brom]

I know everyone says that mk1 brakes are terrible. But lately i've lent my car out to a few people who have all come back and said how scary it was. I'm used to it now as they work fine just feel like your kicking a brick wall.

But yesterday I measured the vaccum pressure into the booster to be below 3 PSI (maybe i mean -3psi?). How does this compare to normal. Perhaps my air pump is shot on the diesel as opposed to the manifold vacuums on other golfs. Does anyone know if rebuild kits are still available for the vacuum pump?

[Peter Jones]

The booster doesn't help the brakes work any better. It just makes them easier to operate.

Are they scared because because the brakes don't work or are they simply not used to having to actually press on the pedal?

How are you measuring the vacuum?

Rebuild kits are available , they've been mentioned on here before.

I think it might just be a case of current generation drivers being too soft

Imagine if they got into a beetle with no vacuum assist at all!

Pete

[Peter Jones]

Oh, and I'm not sure why everyone makes that "MK1 brakes are terrible" comment. They actually work really well so long as they're maintained properly.

Pete

[Brom]

Are they scared because because the brakes don't work or are they simply not used to having to actually press on the pedal?

How are you measuring the vacuum?

Rebuild kits are available , they've been mentioned on here before.

I think it might just be a case of current generation drivers being too soft

Imagine if they got into a beetle with no vacuum assist at all!

Pete

Haha. My last car was a beetle. Thats why i'm not too worried. The brakes are working fine just are so hard. The standard rear drums do look so small though.

I measured with a pressure/vacuum guage by disconnecting the vacuum hose from booster and measuing there.

[Peter Jones]

The rear drums can be swapped for Cordoba ones which are bigger. They bolt straight up. I swapped mine over because I had a set and because everything is much newer. See http://www.vwwatercooled.org.au/newf...t=cordoba+drum

The booster accumulates vacuum, so you'd probably need to T the guage in to line after the one way valve to see how much it's holding. You'd get an idea whether or not the booster is leaking too.

If it really bothers you, you can always fit a bigger booster but in your case I'd rebuild that vacuum pump first.

http://www.vwwatercooled.org.au/newforum/upload/showthread.php?t=11689

Check your flexible brake lines too, they're usually well overdue for replacement after 30 years.

Pete

[Jarred]

It's possible the master cylinder is a bit old and warn too, which would contribute to "poor" brake response.

Good upgrade to do with the Booster IMO. One of my projects for summer.

[Golf Loon]

I can hook you up with some cheap cordy drums and a bigger booster / master if you like.

[Brom]

I'm going to try and rebuild the vacuum pump forst of all as the brakes on the old 5 door were an issue before i removed the engine and this is the only common part. I'll get some new drums on the back too as theyre badly worn. Can't really afford an upgrade yet. But maybe later on.

Also where is the one way valve that allows the booster to accumulate a vacuum. i should probably check its working fine.

[Peter Jones]

I'm going to try and rebuild the vacuum pump forst of all as the brakes on the old 5 door were an issue before i removed the engine and this is the only common part. I'll get some new drums on the back too as theyre badly worn. Can't really afford an upgrade yet. But maybe later on.

Also where is the one way valve that allows the booster to accumulate a vacuum. i should probably check its working fine.

It's in the line between the booster and the pump. MAybe it's part of the pump itself, but I'm pretty sure I remember pulling one out of a diesel at the wreckers.

It might be cheaper to put a cordoba drum setup on the car than replacing the stock drums. I'd check some prices first. Remember with the Cordoba setup you're getting newer cylinders, linings, drums and wheel bearings too. Your new drums will require wheels bearings too which adds to the cost.


Pete