Master Brake Cylinder

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ThomasDahl
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Master Brake Cylinder

Postby ThomasDahl » Mon Oct 07, 2019 7:02 am

One thing is for sure... If I had know what a total hassle changing the master brake cylinder was going to be I would have driven the darned car off a cliff... Only kidding.. But seriously.. Needing to strip out the front suspension to get the torsion bar out... really?

I am now replacing trunions, bushes etc etc. A nightmare as everything is covered in 4mm of Mike Sander. I am now a grease monkey.

I am sorry if this question had already been answered elsewhere, but I was expecting a T-piece at the back of the cylinder and instead found one piece blocked off like the attached photo. Made getting the bas***d out a lot easier as it simply slid back from then pusher rod. No need to undo anything linkage related. But is it OK to leave it like this? It looks like the only pipe connected to the cylinder feeds to a T-piece upfront in the car and from there it is run backwards and forwards in the car.

Bear in mind that this is my wife's car which she has driven every day for 37 years here in Germany. It has obviously worked well for a long time.

Just thought that I would ask..

Best Regards Thomas
Attachments
MB.jpg
Blocked rear end..
MB.jpg (157.55 KiB) Viewed 1168 times
MBhole.jpg
The pit of evil
MBhole.jpg (239.2 KiB) Viewed 1168 times

kennatt
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Re: Master Brake Cylinder

Postby kennatt » Mon Oct 07, 2019 7:09 am

no need to strip, do a search,simply bend torsion bar down with lever and it comes out,put bolts in other way round for future removal,as long as they don't touch the torsion bar.

philthehill
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Re: Master Brake Cylinder

Postby philthehill » Mon Oct 07, 2019 8:14 am

The pipe serving the rear brakes would normally go from the rear of the master cylinder (where the bleed nipple is fitted) through the chassis leg and cross member to the flexible rubber hose serving the rear brakes.
I suspect that for ease of maintenance the 'T' piece has been fitted outside the chassis leg and the pipe now runs rearwards outside of the chassis leg to the rubber hose. As you have found it makes life a lot easier.
The bolts holding the master cylinder are special and have thinner heads. I would not recommend turning the bolts the other way round as the torsion bars does not only rotate but under turning load it bows and can hit the bolts damaging the torsion bar.
As above there is no need to strip the front suspension to withdraw the bolts - use the search facility to get ideas of how to depress the torsion bar to allow the master cylinder bolts to be withdrawn.

Here is one idea:-

viewtopic.php?f=4&t=66986&p=608221&hili ... al#p608221


IslipMinor
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Re: Master Brake Cylinder

Postby IslipMinor » Mon Oct 07, 2019 11:05 am

If the rear brake pipe has been re-routed to the front, has a servo been fitted? If so, to get it to work on all four wheels, the rear pipe has to be re-routed to a front t-piece, connected to the servo outlet, and then routed back to the rear axle.
Richard



ThomasDahl
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Re: Master Brake Cylinder

Postby ThomasDahl » Mon Oct 07, 2019 6:17 pm

Brilliant.. Thank you. Yes, I have a brake servo. Fitted in Bath about a century ago. I never realised that this could be a reason. Makes sense now that I know.

Unfortunately I have stripped out the front suspension so have to rebuild it.

Does appear to be a very sensible modification in any case as it simplifies the MBC removal (other than the suspension nonsense).

Thank you.

psafloyd
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Re: Master Brake Cylinder

Postby psafloyd » Wed Dec 04, 2019 3:05 pm

I did this years ago with a couple of very large screwdrivers. Much better to have it fitted that way round and will need to dig out the MC soon as totally knackered.
kennatt wrote:
Mon Oct 07, 2019 7:09 am
no need to strip, do a search,simply bend torsion bar down with lever and it comes out,put bolts in other way round for future removal,as long as they don't touch the torsion bar.

newagetraveller
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Re: Master Brake Cylinder

Postby newagetraveller » Wed Dec 04, 2019 3:51 pm

Regarding the bolts and nuts holding the master cylinder in place. I ground down the nuts to half their original thickness and ground down the bolts by a similar amount then fitted the bolts the opposite way round. They do not touch the torsion bar and I have done many tens of thousands of miles without any problems.

jagnut66
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Re: Master Brake Cylinder

Postby jagnut66 » Wed Dec 04, 2019 4:04 pm

I have spoken to others, who all seem to agree with you, in that reversing the retaining bolts for the master cylinder is a bad idea and that reversed they could damage the torsion bar.
However, having just viewed the topic attached by 'philthehill', I have to say I had no idea the torsion bar would be that flexible.
The jacking the car up with a strap around the torsion bar (pulling it down out of the way) example seems the best way of keeping it in place, whilst you remove, do what you need to do and then replace the master cylinder.

It would be interesting, if anyone has any pictures, to see on here the damage that is caused (to the bar) by the bolts being reversed.
It would make the point too.
Best wishes,
Mike.
1954 Series 2 on axle stands needing more welding......

Sleeper
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Re: Master Brake Cylinder

Postby Sleeper » Thu Dec 05, 2019 6:39 am

" The jacking the car up with a strap around the torsion bar (pulling it down out of the way) example seems the best way of keeping it in place, whilst you remove, do what you need to do and then replace the master cylinder. "

John :wink:

ianmack
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Re: Master Brake Cylinder

Postby ianmack » Thu Dec 05, 2019 7:58 am

Years ago I fitted a master cylinder with the bolts the ‘wrong’ way round. On extreme bumps there was a knock as the bar hit the bolt ends. I added washers under the bolt heads until the bolts did not protrude significantly from the nuts and heard nothing more. There was no visible damage to the torsion bar.

I have fitted two cylinders since in this way and it works fine.

don58van
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Re: Master Brake Cylinder

Postby don58van » Thu Dec 05, 2019 8:23 am

I like Ian's solution. I have used G-clamps and chunks of wood in the past.

In my view, anything that makes servicing the master cylinder less diabolical is worth serious consideration.

Don

moggiegeek
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Re: Master Brake Cylinder

Postby moggiegeek » Sun Dec 08, 2019 5:28 pm

To pick up Islipminor'ls point. Is there any advantage in plumbing in the master cylinder so that all four wheels have servo assistance?
If so would that also be true with Riley fronts and Wolseley rears?

philthehill
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Re: Master Brake Cylinder

Postby philthehill » Sun Dec 08, 2019 5:50 pm

The servo should be effective on all four wheels. It makes no difference if you have Minor, Wolseley or Riley brakes.
If you have servo assistance on the front brakes only - under hard braking the fronts are very much more effective than the rears and the loading on the rear brakes/tyres/road becomes lighter so increasing the possibility of wheel lock which can lead to the driver loosing control of the car and spinning.

The brakes need to be fully balanced between front and rear. Fitting a rear brake line/fluid adjustable pressure limiting valve is the best way to optimise braking over all four wheels.



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