15 replies to this topic

[Dusky]

Hi

Reinstalled my engine today and the pesky brake servo was once again something I did not like having in my way.
Was planning on removing it anyway, whats involved in removing the servo and fitting a different master cilinder?

Cheers

[nicklouse]

So what do you have! Remote or attached (on a RHD car) LHD has rods across the bulkhead or something.


If remote just relocate somewhere else. Dual circuit and servos I never had.

[peter-b]

Just turf it in the skip bin and wack an earlier style dual circuit m/c on, bolts straight on and you might even be able to use the original pipes, just check threads. It'll stop fine, Aussie LS1275's never had boosters. Real men don't need boosted brakes.

[666junky]

If you drive a rhd mini it isnt that straight forward. You need to replace the servo unit with the duel master cylinder (upright thing). And you must replace the brake pedal as the two are different (servo has a rod attached, non servo doesnt). With the brake pedal you also need to swap the return spring that sits on the pedal spindle, if you dont you wont have a springy pedal! Then you need to think of routing the brake lines.. due to the servo the bias valve is further to the left of the bulkhead which means the generic brake line kits for the new master cylinder wont reach that far. The M cylinder also has different sized holes (10mm and 12m i think!) So the imperial ones dont fit anymore. Have a look and see what youve got before pulling it all out!

Edited by 666junky, 09 May 2015 - 07:41 AM.

[peter-b]

Can't you just reroute the pipes to right shape and fit the right nuts if the threads are different? Then drill/grind the rivet off on the pedal rod, the upright M/C has the rod on it. 

[Dusky]

Will have a good look,
It is a LHD car with the servo mounted in the engine bay, it look like its directly attached to the MC.

[Dan]

Can't you just reroute the pipes to right shape and fit the right nuts if the threads are different? Then drill/grind the rivet off on the pedal rod, the upright M/C has the rod on it.

The servo clevis pin is bigger than the cylinder pushrod one so what you would have to do is remvoe the pedal from the car, drill the old rivetted pin and remove the push rod, match drill the clyinder clevis and pedal to suit a larger clevis pin and then reinstall everything. If you don't do that you get a fairly noticeable amount of additional lost travel and the clevis pin wears as it slops around. It's easier to swap the pedal.

The servo itself isn't in the way of anything. The easiest solution is to replace the hard lines running from the M/C to the FAM7821 valve with flexible lines. Then you can easily move the cylinder out of the way without disturbing the system. The flexible lines are available as kits from the bigger specialists.

Given how tight you've said in the past that some of your MOT rules are over there, how legal would ditching the servo be?

[Dusky]

Hmm, MOT is indeed something I should think about ;

although I don't think they would notice the difference ( they don't know that much about mini's, only obvious things are forbidden). ( Like braided brake hoses as a stupid example)

 

ANyway, my biggest reason for ditching the servo is that I don't use it now. ( It's disconnected). But a little question :  Does the servo always draw air? Or only when braking? And can I check it for air leaks?

 

thanks, you guys are great! ;)

[sledgehammer]

the master cyl can be unbolted from the servo & gently moved over to the wing - giving a lot more room

 

only do this if the pipes are good - if the pipes are old , they probably needs replacing anyway also watch out for fluid spilling out

 

done loads of engine swaps that way

 

servo only releases air into manifold after use - to equalize with manifold vacuum - (revs should increase after pedal is released for a sec)

Edited by sledgehammer, 09 May 2015 - 11:12 AM.

[madaboutcherry]

good old minispares

http://www.minispare...h/classic/servo pipes.aspx|Back to search

[cmonson]

I know that this thread is a bit old.  I am getting ready to ditch my brake booster for a standard master cylinder 

I have a LHD Mini with a brake servo (and the cross-over bar for the pedal) 

I have purchased the dual port upright master cylinder as well as the pipe kit that Mini Spares sells

 

I am assuming that I can just remove the entire booster and brake setup in the engine compartment.

Remove the rod that connects the crossover bar to the servo mechanism in the engine bay and install the new master cylinder and brake lines.

 

It is that straight forward?  Or is there some other customization needed? 

[Spider]

You'll need the Master Cylinder as you've already mentioned and also an earlier LHD Pedal Box along with the pipes.

[cmonson]

You'll need the Master Cylinder as you've already mentioned and also an earlier LHD Pedal Box along with the pipes.

My goal is to actually mount the master cylinder on the right where the booster is now.  Utilizing the crossover bas that's already in place.  trying to avoid replacing the pedal box

[PeteD]

Also doing this delete, was wanting to check, does the front brakes from the bias valve plumb into the top of the GMC227? Looking at some diagrams is seems the pre GMC227 the front brakes are plumbed in the bottom and the GMC227 they are at the top, this correct?
Thanks

[bpirie1000]

Also need to blank off the vacume on the manifold.