Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Brake servo overheating in Plus 8

Hello, a new member with a problem. Had an RPI sports exhaust fitted & now in warm weather and in traffic experienced the brake pedal movement gone and rear brakes applying. It a 96 Plus 8 with alloy rad, kenlowe fan, plus I've tried bonnet extension brackets, heat shielding, exhaust wrap, moving reservoir to bulkhead and DOT 5 fluid the problem persists. I think the under bonnet heat and the proximity of the exhaust manifold to the servo causes the brake fluid to expand thus applying the rear drum brakes? Anyone else experienced this and all help much appreciated. Thanks

Welcome, I have an RPI manifold on my Plus 8. I had to make up a new heat shield and squeezed it in between the manifold and the servo. The heat shield is curved up over the reservoir. Following bringing out to Australia I had to get the manifolds ceramic coated to bring down the under bonnet temperatures.

Hi, I have a 96 +8, the same as yours, and have stainless manifolds and pipes etc from Mulfab. I suspect the proximity to the brake fluid reservoir will be very similar as there is little room. Mine came with a heat shield from Mulfab with brackets that is bent and wrapped over the exhaust near the reservoir to stop it getting hot. Even though under the bonnet gets very hot I have never had loss of brakes due to heat getting to the fluid in the reservoir. Give Peter Mulberry a ring I am sure he could supply a heat shield that will work. Mulfab

Alternatively why not speak with RPI they have years of experience with V8's including Morgans.

Thank you so much both. I'm not sure I have the skills or tools to make a heat shield so will call Mulfab and RPI to see what they can do. I've suffered the problem for 4 years and just wish I had joined this forum earlier! Thanks again and will post update when progress is made.

My servo definitely overheats and pedal creeps up,not got as far as locking rear brakes yet (although i keep checking)
95 +8 with standard (cast)manifolds and twin exhaust system.
hydraulic reservoir is swathed in insulation.....

I have exactly the same problem with my 95 +8, which has a manifold from Librands. I was going to try fitting some additional heat shielding to the reservoir, but it sounds from other posts that this might not be enough. Hopefully someone will come up with the best solution.
Regards
Colin

Have now fitted heat shield to the servo, proper metallic sheet and mounted a curved sheet beneath the manifold where it exist the engine bay. I'll be doing a long drive later this week so we will see if it works. Maybe the next step is the special cowl with the air scoop under the rad?

Well, the heat shield fitted around the servo and under the exhaust manifold has not solved the problem. Asking around the best advice seems to be to have the manifolds ceramic coated as per Paul55 above. Sounds like a winter job and have been recommended to use Zyrotect (I think that's the name)

Doing a quick search, it looks like it's Zircotec. It will be interesting to see if this works ( and how much it costs !)

I've used Zircotec sheet in the past. It is very effective and not too pricy. The company is excellent to deal with.