Marlin Hunter V8 - Dual servo

[monomer5]

Mechanic has fitted the suggested 7" dual servo upgrade to my Marlin Hunter, but now it seems that the bonnets doesn't close !! Any thoughts/suggestions (positve ) anyone ?
Many thanks

[greyV8pete]

Re: Marlin Hunter V8 - Dual servo

I guess that as it faces “uphill” moving the master cylinder forward has raised the front enough to foul the bonnet? With the bonnet open rest a thin wood batten across the front and rear bonnet tape and you can see what the problem is. Have you got a fluid reservoir on top of the master cylinder? If so that is most likely your problem. You then need a remote reservoir and connectors like the photo below.

As a matter of interest what engine do you have and do you have discs or drum brakes at the rear? Peter.

72B77AD4-5A69-4821-8A0C-28411A98C821.jpeg

[monomer5]

Re: Marlin Hunter V8 - Dual servo

Many thanks Peter for the very swift reply - much appreciated. The mechanic has the duel servo flush against the housing plate i.e perpendicular to it . In this position, the master cylinder is actually fouling the side panel, and not the bonnet as I was told before. He is thinking of cutting the plate back and re-welding so that the servo sits closer to the rear plate. Another option would be to use spacers/washers on the outside studs to align the servo at an angle towards the engine, but that doesn't look correct . What do you reckon ?

Forgot to add that the Hunter was built by Marlin in 2001 for the late actor Warren Clarke. Engine is 3.9L Rover V8

[dcunn]

Re: Marlin Hunter V8 - Dual servo

Hi My Hunter had spacers to make this mod work and didn't look bad at all

Contact me on my email as in Pitstop and I can send you pics

By the way, for the archive can you please tell me the full sequence of letters/numbers
on your cars plate...T4 etc

Thanks Dave VUnnington

[monomer5]

Re: Marlin Hunter V8 - Dual servo

Hi Dave thanks
T4-223KRKRTCLH0901MC
Will email you
Cheers
Clive

[dcunn]

Re: Marlin Hunter V8 - Dual servo

Cheers for the numbers Clive, I answered your email before I checked this site !

So Warren Clarke must really be M Clarke ???

[monomer5]

Re: Marlin Hunter V8 - Dual servo

I can clear up the MC mystery . Warren commissioned the car for his wife Michele as a birthday present. I guess she may have found it tricky to drive as they returned it to Marlin. I bought it from Terry in 2003. Its nice to know the provenance. I have build photos and even some when Terry delivered it to them !
Cheers
Clive

[greyV8pete]

Re: Marlin Hunter V8 - Dual servo

Ah yes as Dave says above I remember that my servo has packing washers on the outer two studs to tip the servo at an angle. The resultant gap is filled with black silicone sealant so looks acceptable. That said be aware that that does cause a potential mismatch angle between the brake pedal axis and the servo push rod. On mine the outer clevis hole was filed slightly elongated to overcome this. A more elegant engineering solution is to fit a rose joint. That also gives its own problems due to thread differences and rose joint length required. One was is to weld a threaded adaptor bush to the rose joint. Plenty of info about this if you search dual servo on the Cabrio / Hunter forum.

Another option is to move the whole pedal box back. It is separate from the bulkhead and fixed to it with bolts, so using spacers is an option to achieve this.

You have the same engine as my Hunter. Hopefully you have disc brakes at the rear? Peter.

[monomer5]

Re: Marlin Hunter V8 - Dual servo

Many thanks Peter. Yes, sorry I should have responded earlier - discs all round

[greyV8pete]

Re: Marlin Hunter V8 - Dual servo

Many thanks Peter. Yes, sorry I should have responded earlier - discs all round

Aha! Ditto here. Am sending you a PM. Peter.

P.S. I seem to think that on later Hunters Marlin angled the front of the pedal box to avoid needing the packing washers? The pedal / servo angle issue remains though. Peter.

[monomer5]

Re: Marlin Hunter V8 - Dual servo

Thanks again. Yes, I think the angle can be solved with your rose joint suggestion. I'll post a photo to show you, but when the new dual servo and master cylinder are joined and then bolted on the bulkhead, it protrudes so that the side panel wont fit .

[Mike]

Re: Marlin Hunter V8 - Dual servo

Thanks again. Yes, I think the angle can be solved with your rose joint suggestion. I'll post a photo to show you, but when the new dual servo and master cylinder are joined and then bolted on the bulkhead, it protrudes so that the side panel wont fit .

Hi Monomer

It is pleasing to see Hunter V8 owners are still adopting this huge brake improvement- it transforms the car from a “squeaky bum ride” into a sporty car you can push on with confidence.

As an update to the upgrade, please make sure your brake pedal has a reasonable return spring fitted (one from an early Landrover has been effective for several owners). Several owners reported issues with brakes binding after being used.
The issue seems to be the dual servo not self sealing properly, with the resulting slight vacuum leak applying a small amount of pressure on the master cylinder. After several miles of this the brakes get incredibly hot.

A reasonable return spring ensures the servo self seals and the brakes work incredibly well.

Do you have the photos of Warren sat in the Hunter? Marlin sent me copies years ago as I love the paint finish on your car.

Good luck with getting the servo installation to fit. Sounds like a couple of washers should do the trick.
Regards
Mike

[greyV8pete]

Re: Marlin Hunter V8 - Dual servo

Aha! Ditto here. Am sending you a PM. Peter.

P.S. I seem to think that on later Hunters Marlin angled the front of the pedal box to avoid needing the packing washers? The pedal / servo angle issue remains though. Peter.

Hi again. Did you receive my PM ok?

[monomer5]

Re: Marlin Hunter V8 - Dual servo

Thanks Mike and Pete for your help on this. Mike, sorry, no photos of him sitting in it - but will go back through my photo box. New dual servo has been fitted and braking seems to be working well. I was getting very hot rear brakes but this seems to have been due to sticky calipers . The car hasn't been used for several years. I think this has cured the problem, but will take up the suggestion to fit the return spring on the brake pedal . Will post some photos later.

[monomer5]

Re: Marlin Hunter V8 - Dual servo

Dual servo fitted.jpg