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MG TD TF 1500 - Thread sealer - water plate on head

I'm sure that this has been discussed many times. Please answer it again.

>> What should I use to seal the cork gasket and threads on the short screws that hold the water block-off plate on the back of the cylinder head (TF-1500)?

I removed it today because water has been weeping from the cork gasket or from the screws. The plate is about two years old; no rust holes and is not mushroomed from overtightening.

I want to stop the leaks, but don't want to use something that is near impossible to remove or that is difficult to clean from the threads in the head and cause problems the next time that I remove the plate.

Permatex #3 Aviation?
Permatex Super 300?
Other?

Thanks,

Lonnie
TF7211
LM Cook

Permatex Aviation sealant
George Butz

Peramatex is what I used...until I eventually gave up on the cork gasket and bought one of Tom Lange's cover plates. Bolt it under your original plate and you will never have a leak again :-)

Dave
D Moore

Get rid of the cork gasket! I like vellumoid gasket paper.
Contact glue on 1 side of the gasket, grease on the other side, of the gasket. You can then remove & replace many times and not need a new gasket.
Teflon tape on the threads.
Len Fanelli
Abingdon Performance
Len Fanelli

Thanks everyone for your replies

Len - Never thought of Teflon tape on the screws. I'll use it.

I'll give cork one more chance. Hope that I don't have to eat my words.

Lonnie
TF7211
LM Cook

Cork works fine but you have to seal it properly. Right Stuff is the best sealer I've found for cooling system gaskets. Most of my engines are sealed with it. You can use it on the threads also if desired.
Steve Simmons

I thought the 4 threaded holes were "blind holes" not drilled and tapped all the way through the casting and into the water chamber and therefor not needing to be sealed. Am I mistaken about this?

chuck
cj schmit

Chuck, on my TD 3 holes tapped through . I Put a tiny bit tread sealer ( Permatex ) on them .

Lonny, most of the original plates are warped and corroded inside. Best advice ?? buy the stainless from Tom Lange,... problems solved.

Gerard



Gerard Hengeveld

Better solution get some 6mm plate or flat bar and fabricate your own, removes all distortion issues and wont rust out in your lifetime.
G Evans

In the gasket kit isn't this a paper gasket, not cork? I guess if you're thinking about modifications perhaps also replace the slot head machine screws with bolts for ease of access. Cheers
Peter TD 580
P Hehir

I fabricated mine from 6mm flat plate and used hex head set screws for ease of future access if needed.
John...Sydney
John Walton

Mine is made from brass plate. Solid, won't corrode and cost nothing. No one can see it anyway, so no worries about it not looking original. But I still painted it engine color. :)
Steve Simmons

Peter, the gasket is cork.
I only use Teflon tape on home plumbing. I use permatex thread sealant. It is an automotive thread sealant. Regards, tom
tm peterson

I dont feel comfortable having brass and cast iron mated with each other sharing the water jacket, surely its a lethal combination for electrolytic action especially when combined with heat.

Use of teflon tape in automobiles has been debated previously, there are many varieties of this product designed for specific purposes. Here is a link:

http://www.allsealsinc.com/pdf2/Teflon%20Tape.pdf
G Evans

Then you'd better remove the drain taps, radiator, thermostat and possibly your water pump impeller!
Steve Simmons

Thanks everyone for your help and information. I installed the plate onto my cylinder head.

I ended up using Permatex Aviation Form-a-Gasket on the cork gasket and on the screw threads. No water leaks.

Don't know how difficult Permatex will be to clean from the threads inside the head if I need to remove the plate. Especially the hole that does not go all the way through.

I snugged the screws when I installed the plate, then tightened a little more the next morning. I learned a couple of years ago that tightening too much will split the cork gasket.

The cork gasket from Moss has a portion of one long side cut out (same as the paper gasket for the water outlet pipe). Doesn't seem to have a purpose, so I cut my gasket without it. The illustration in the WSM does not have the cut out.

I'm concerned how long my two-year-old plate from Moss will last. It is already showing signs of corrosion ... rough pitted surface & rust, but not flaking. The one that I removed two years ago looked similar and had a pin hole leak where it had rusted through. Don't know how long it had been on the car.

The two-year-old coolant was clean, clear, and looked new.

I used a Harbor Freight right angle ratchet screwdriver to remove & tighten the screws. It has a bit with an especially wide straight tip that fits the wide screws. The screwdriver is no longer available ... replaced by one that has a bigger head and is difficult to get between the head and the firewall; it doesn't have the wide bit.

Lonnie
TF7211
LM Cook

At the risk of upsetting the ultra-purists, I replaced the flat head screws with hex head. No one has ever noticed, and I thanked myself the day I had to remove that plate with the engine in place!
Steve Simmons

This thread was discussed between 22/03/2016 and 24/03/2016

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