Brake master cylinders for Landrover-C303 axle conversion

Avox · Gate Opener Joined: 16 May 2008 Odometer: 3

Hi Everyone,

We have a pair of C303 axles fitted to our SWB Series III land rover. I have noticed that there have been other questions regarding the brakes when you make these sorts of conversions. We had problems with the pedal going all the way to the floor so we changed our master cylinder to a 6 cylinder one from a 109. This has made very little difference despite much fiddling with adjustments and you still have to pump the brakes to get them to bite. I have heard that 101 master cylinders have a bigger stroke volume? Is this the case? Would a booster fitted to the pedal make any difference?

Would value any advice because it would be nice to improve the brakes a little!

Cheers.

Avox · Gate Opener Joined: 16 May 2008 Odometer: 3

Dennis,

Thanks for your quick reply. I am interested to hear that you have done a few of these conversions. I have talked with my Dad at length following your response. We have previously done all the checks that you talk about and there is definitely no problem with the mastercylinder/servo unit. When you tie off all 4 hoses the pedal is rock solid so I don't think we have any air in the system. We will re-check all 4 wheels individually though.

My only other thought is that we might not have been supplied with a true 6cylinder 109 mastercylinder. Do you know how big the internal dimensions of the 6 cylinder stroke volume are because then we can check it against the '6 cylinder' one that we have to make sure that we do infact have the right mastercylinder. When we measured the '6 cylinder' that we have and compared it to the original mastercylinder it was only a tiny bit bigger which obviously means the difference in stroke volume is very small? Do you know what size the original volvo masterclinder stroke volume is? Would be really useful to have some dimensions so that we can work out whether we have the correct mastercylinder in the first place.

Many thanks

Patrick

RichardD · Posted: Fri May 16, 2008 3:21 pm Post subject:

Patrick
a couple of guys have fitted Volvo master cylinders or found some other larger volume aftermarket unit.

The problem is, indeed, volume becasue the drums require more than discs.

Anthony · Off-Road Guru Joined: 05 Mar 2007 Odometer: 1640

it may well be that drums require more volume than discs but he has a Series Landrover has he converted to discs, I did not see that.

if he is using drums then there should not be an issue other than a lack of power possibly if he does not have a servo. Though I see on a subsequent post he mentions a servo. The brakes on the Volvo are the same as you know as some Landrovers like the 6 cylinder and the 101FC what he seems to be experiencing is a lack of brakes at all if his pedal goes to the floor surely. Does this not suggest some other problem along the lines of what Dennis is suggesting? I can see that if the volume were insufficient then peddle travel might run out but he is saying that he has a master cylinder from a LWB perhaps it s not the right LWB that he has chosen I do not know.

lee · Posted: Sat May 31, 2008 10:46 am Post subject:

I put the volvo M/Cyl into my 90 and it made a huge difference. I also reworked all the brake lines to closer emulate the standard volvo setup.

I made an adapter plate that bolts onto the standard landrover servo and sealed everything up. I cannibalized an old ford escort for its brake reservoir and everything seems to be fine.

It not as good as disk brakes, but it will hold on a hill.

Lee