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Thermostat leak

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RadfordJim
Posts: 140
Joined: Tue Feb 16, 2016 10:19 am
Location: Coventry

Thermostat leak

Post by RadfordJim »

I have an annoying little coolant drip from the bottom of the thermostat housing on my SP. I'm going to strip and clean, but on reassembly is it best to use:

1. A new original type gasket with no sealant.
2. Ditto with sealant such as Hylomar blue.
3. No gasket using Hylotyte Red on both surfaces.

Advice gratefully received as I only want to do it once ;)
Jim in Coventry - Home of the Daimler

User avatar
RadfordJim
Posts: 140
Joined: Tue Feb 16, 2016 10:19 am
Location: Coventry

Re: Thermostat leak

Post by RadfordJim »

I now know the reason for the leak. The two bolts securing the thermostat housing are 1" long and bottom out before the cover is tight. The parts catalogue shows 7/8". The previous assembler used a copious amount of black sealant with the gasket but this has failed over time. I'll shorten the bolts using a 5/16" nut to run back and clean the thread.
I'd still be grateful if a wise person could advise me on the original question :)
Jim in Coventry - Home of the Daimler

classiclife
Classic Wise Man
Classic Wise Man
Posts: 1601
Joined: Wed Sep 05, 2018 9:55 am
Location: Ridgewood - East Sussex
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Re: Thermostat leak

Post by classiclife »

Hello Jim,

I always use a light smear of sealant on both sides of the gasket for my classics - works every time for me.

My usual choice is Granville Instant Sealant - via Halfords / Amazon / eBay plus other motor factors.

https://www.halfords.com/tools/garage-e ... _ZEALw_wcB

Hope that assists and well done for solving the leak - as you say, poor choice of securing !!

Regards.

Richard.
1968 Daimler V8-250 Saloon
DLOC East Sussex Branch Secretary
DLOC 2.5L V8 & V8-250 Registrar - https://www.dloc.org.uk/v8-250
DLOC 2024 International Rally - https://www.dloc.org.uk/rally-2024

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Kbeal
Posts: 148
Joined: Mon Feb 15, 2016 9:01 pm

Re: Thermostat leak

Post by Kbeal »

I’ve only ever used the gasket - no leaks in 27 years (tempting fate!)

Kevin

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