GT6 mk3 master cylinder clashes with the bonnet

[Kevin.payne.15]

Ok so I thought I would tidy up the bulkhead and bought fron the club shop some very nice black clutch and brake master cylinder support brackets

 

Clutch fits fine.

 

Fitted the brake this weekend and the master cylinder fouls with the bonnet. According to Garth I had a spit bracket on before and an incorrect master cylinder and hence it works. Remedy is either new old stock master cylinder or new brackets

 

Mine currently has a plastic fluid resovoir

 

I can't find anyone who has the cylinders these days. Any clues where I can get one or an alternative.

 

Ta kevin

[Pete Lewis]

Land rover do a non angled slightly larger bore cyl for around £12 used by many

this will raise pedal pressure but reduce stroke.

mang sold on e bay as uprated....not a good phrase its close to and cheap but not uprated

 

not overly approved but its a very cheaper option

[dougbgt6]

If your GT6 is a late one, after Feb 73 it should have a 0.75 bore master cylinder. If an earlier model 0.70 bore. Doesn't sound like much difference but I thought I had trouble with my 0.75 so fitted a friends spare 0.70 and pedal travel went 3/4 of the way down, quite scary! The 0.70 had a plastic reservoir and fitted fine.

 

Kevin, while I had the reservoir off I removed the bracket, de-rusted and repainted it, came up very well, that would solve your problem, is it an option for you?

[Steve C]

Hi Kevin

 

Have you tried this lot?

 

http://www.demon-tweeks.co.uk/motorsport/brake-master-cylinders-reservoirs

 

Regards

 

Steve C

[Guest]

Hello Kevin.

 

Checking my suppliers list, try the following - all are A1; especially David Kingerley & Coasting Ltd.

 

David Kingerley - 07977.914.088 / 01332.873.685

 

Coasting Ltd - 07973.710.473

 

JCL Classic Car Spares - 07831.720.023 / 0116.235.5348

 

J&L Spares - 07860.494.772

 

Hope that assists ??

 

Regards.

 

Richard.

[Kevin.payne.15]

Hi. Thanks for responses

 

Yep mine is a late mk3 that I'm told should have a 0.75 bore

 

Currently it has a plastic resovoir so suspect that it's a 0.7 on there currently.

 

I'll try the above suppliers. Any idea what part number I'm meant to be asking for.

 

Yes considered the option of reworking the old bracket but the flanges where it bolts to the bulkhead are a bit distorted round the holes - might order a spit replacement fron the club shop and see if that fits as well

 

Any advice on how to get the rubber boot to fit to the bulkhead. I tried for an hour then gave up and cooked supper instead

 

Ta. Kevin

[Kevin.payne.15]

My reason for questioning the part number is that whilst rammer quotes gmc219 I've found from experience that this isn't necessarily correct and my parts manual only quotes up to ke200001 and mine is post. What's the difference between a 209 and a 219. Does anyone know?

 

Regards kevin

[Pete Lewis]

Looks like its the variant in bore size

[dougbgt6]

Yes, the rubber boot is an absolute bugger to get back on. 0.75s do come up regularly on Ebay, just keep watching.

[John Bonnett]

The boots respond well to a heat gun and soften sufficiently to be pushed in place in just the same way as a grommet.

 

Clearance between bonet and reservoir lid is always going to be close but no matter which master cylinder you fit it should clear. And the Spitfire and GT6 mounting brackets are I believe the same.

 

So my thought is to lift the front of the bonnet on the hinge box adjusters. Perhaps worth a try.

[Kevin.payne.15]

Ah. After speaking to Garth then I now understand. The appature hole on the spit brackets are actually ~10 mm lower than on the gt6 but the actual bracket is about the same size. Called round suggested suppliers and the cheapest solution s to get a spit bracket and fit that. Even if I by a clutch one to match then it's less than half the price of a cylinder

 

I'll offer the redundant one to the local group.

 

If anyone feels like taking a photo of their bulkhead for the brake pipe runs then would appreciate it. Mine are a mess. Email is k.cpayne@blueyonder.co.uk. Ta kevin

[John Bonnett]

Ah. After speaking to Garth then I now understand. The appature hole on the spit brackets are actually ~10 mm lower than on the gt6 but the actual bracket is about the same size. Called round suggested suppliers and the cheapest solution s to get a spit bracket and fit that. Even if I by a clutch one to match then it's less than half the price of a cylinder

 

I'll offer the redundant one to the local group.

 

If anyone feels like taking a photo of their bulkhead for the brake pipe runs then would appreciate it. Mine are a mess. Email is k.cpayne@blueyonder.co.uk. Ta kevin

Hi Kevin,

 

Here's a picture of the pipe runs on my car.

 

rgds

 

John

[dougbgt6]

Kevin, on a late GT6  there should be a T piece on the brake pipe near the battery compartment. One feed goes down the bulk head, under the car, to the rear brakes and the other to the servo. The servo then feeds the front brakes only. Don't forget to put a loop in the clutch pipe to allow for the engine flexing.

[Pete Lewis]

As OE the brake bracket generally has short rib welded across the mount face to stiffen it

as brake takes much higher loads than the clutch

 

pete

[Kevin.payne.15]

Well that's a surprise. My servo applies to the whole system on mine! No wonder the rear brakes lock so easily when I tested them on a run last year. I fear the replumbing will be a bigger task than originally envisaged. Is it normal only to apply to the fronts? Suspect it will make a significant difference so I take its its recommended? Clutch pipe has a loop so I'm compliant on that at least. I almost get afraid to ask questions as I find more and more wrong with the project.

[Guest]

That's what makes projects good fun Kevin and interesting for those able to offer advice.

 

Regards.

 

Richard.

[dougbgt6]

Before Feb 73 the servo was an extra and did work on all 4 wheels. As part of the 73 upgrade the rear brakes were upgraded, larger brake cylinders and larger shoes plus the larger master cylinder. I imagine they decided having the servo on all 4 wheels would "unbalance" the braking.

 

How do  I know this? I fitted a brand new servo, which didn't work!  After weeks of fiddling about, head scratching and searching the net I got it fixed. Being no longer scared of it I tried it on all 4 wheels and then back to the front only. There wasn't a lot of difference but there was a tendency to lock the wheels with the servo on all 4. With the front only the car dipped noticeably more at the front but didn't lock the wheels.

 

Swapping the plumbing around was only half an hours work but I would make doubly sure you have a post Feb 73 car before modifying it!

[Kevin.payne.15]

Well mine is exactly Feb 73. It has the horrid self adjusters on the back and metric callipers on the front. Is this sufficient to say it's post 73? I'm not convinced mine is a factory fit servo since it points forward where as most I've seen go sideways and doesn't look like it sits well on the bulkhead Any clues? Kevin

[John Bonnett]

Here's how the original Girling servo mounts.

[dougbgt6]

Quit a few Girling servos have been replaced by Lockheeds over the years, this may be what you have. If you look for a Girling repair kit on Canleys they take you to an ad for a brand new Lockheed!

 

My car was built on 6th February and has the dreaded self adjusters, metric callipers, Sun dim glass, partial cloth sets, reworked breather arrangement from the rocker box feeding into both carbs, firetrap incorporated in the top of the rocker box........ can't think of what else!