Thread: Gav's 101.

I understand the the master cylinder will bolt on the disco booster but some modification to the mounting system is required.

My brakes pull up no issues - the direction you head when braking is the real worry.

Thanks - yeah, the braking is fine but requires a lot of effort if you need to stop in a hurry. Hoping a more modern booster will help with this. And yes, the disks are purely to make direction of travel under braking less of a lottery.

Put a second inline booster in the front brakes brake line - mounted in the tunnel.

That way the standard booster operates the rear brakes and provides pressure to the front brake lines which then oiperate the second booster that just operates on the front brakes - so lots of boost to the front brakes and just the right amount to the rear brakes.

Originally Posted by garrycol

Put a second inline booster in the front brakes brake line - mounted in the tunnel.

That way the standard booster operates the rear brakes and provides pressure to the front brake lines which then oiperate the second booster that just operates on the front brakes - so lots of boost to the front brakes and just the right amount to the rear brakes.

Good idea.
A VH44 is probably what you want. I have one I bought it for the Moke. Haven't installed it yet.
I got it out of a Valiant that had the setup just as Garry suggests.

PBR have them - I had one in my series 1.

Finally got around to looking at the booster upgrade this morning. Whipped the old one and the brake pedal assembly out, and measured up a few offerings I had. The D1 dual diaphragm version is the closest fit, and is not difficult to make work in most respects - I've only found one problem, which I'll describe in more detail later on.

The booster mounts without much fuss onto the existing pedal assembly, and will only require 3 flat plates made up to strengthen where it sits, and allow all the braces to bolt back on. I'm not going to show or describe them here - it's pretty straight forward and if you were to do this conversion and need to ask once your putting it together, then maybe you shouldn't be playing with your brakes. Sorry if I sound like a dick saying that, but it don't want to be responsible for other people's brake systems.

The output rod on the new booster is 25mm too short, and will require a small shaft to be turned up. The connection to the brake pedal pivot is also easy to make work and is exactly the right length.

So, it sits in position nicely and despite being around 30mm thicker than the standard booster, there is still enough room for the master cylinder to fit, while using all the standard lines. Pic below shows it mounted more or less where it will be permanently. It will actually be 4mm further out due to one of the plates that need to go in, but there is still room for it.



This next if shows me holding the master cylinder flush with the booster, but on an angle as it won't sit over the studs - that's the only issue I've found.



The master cylinders mounting holes are slightly narrower than the studs on the booster. The easy bodge for this would be to slot the holes with a grinder and use some big washers on the studs, but there isn't much metal around the mounting holes, so I, not sure if I want to do this yet. I may have to do this, but if that is the case, I'll need to make up a bracket or clamp that can bolt onto the booster stud after the master cylinder that holds the master cylinder securely and takes the strain of the end of the slotted mounting holes. I have a machinist friend who owes me some favours, so I might get him to look at it and make something up.

So, if I can work that out to my satisfaction, then this is quite a straightforward upgrade. Apart from drilling 2 holes, nothing else is changed and can be taken back to standard easily.

There's another newer master cylinder that does fit. Was having a similar conversation this morning with a local 101 owner who has that servo in his. Pete might know..

Cool, if anyone knows of a different master cylinder that will fit, I'm all ears.

I'll be getting the plates and extension shaft made up next week, so hopefully I'll have the booster mounted properly next weekend.