Fitting coolant return flange gasket

The other week I replaced my radiator fan switch. When I ran the engine up to temp it didn't kick in and the coolant boiled over came out the head where the return flange joins the head.

Tested the thermostat and it's trash, flushed the system. So now I have a new thermostat and a gasket for the return flange to fit. Do I need to add a smear of sealant or is it good to go with just the gasket?

Dan

No, you don't need any sealant, however; if you have plastic flanges when is common on later Golfs/Cabriolets then I would suggest that you replace it.
Besure that you clean the metal on the head with sandy paper and or steel wool to get the area clean and flat.

The plastic flanges tend to warp or crack on the ear mountings area as they are really close to the seal on the outside.  Also that on some of the flanges I bought (plastic) had the Steel bolt sleeves were slightly longer than the plastic and I had to file the steel to be even with the flange.

Flange/housing like this.

http://www.ebay.co.uk/itm/MK1-2-SCIROCCO-Cover-Thermostat-Mk1-2-Golf-T4-90-03-055121121F-/361999917898?hash=item5448e0634a:g:gZIAAOSwDNdV3apG


Shop around as 1st one I found.

Thanks both.

It's a metal flange, 1.6 8v GTI, so it'll just need cleaning up.

This one, not the thermostat cover.

http://www.ebay.co.uk/itm/VW-MK1-GOLF-ENGINE-METAL-FLANGE-WATER-COOLANT-PIPE-HOSE-GTI-Cabrio-Jetta-Caddy-/311923915325?hash=item48a01d3a3d:g:KkUAAOSw3xJVfXJk

Dan

Spangle said

Thanks both.

It's a metal flange, 1.6 8v GTI, so it'll just need cleaning up.

This one, not the thermostat cover.

http://www.ebay.co.uk/itm/VW-MK1-GOLF-ENGINE-METAL-FLANGE-WATER-COOLANT-PIPE-HOSE-GTI-Cabrio-Jetta-Caddy-/311923915325?hash=item48a01d3a3d:g:KkUAAOSw3xJVfXJk

Dan

Similar to the ones I retro-fitted metal outlets on my Cabby's as I got so tired of replacing the plastic ones.

BALLS!!!

I've stripped the thread out of the lower hole on the cylinder head.

How do I go about fixing that

Threadsert, or heli-coil When I had the same thing happen to me on a Exhaust (2 ) STUDS I opted to take the head off and have it repaired by a machinist.  I broke them trying to take a Cracked manifold off without using a air-impact, so I learned a Valuable lesson again, never-seize, and Air Impact.

The Cylinder head attachment parts only take 87 inch/lbs of torque, and that is why I usually specify that you use a 1/4 drive in/lbs to set the bolts

Thanks for the help.

Looking at it it may have had an heli-coil in it already. As when the bolt came out, the thread was like a spring wrapped around it.

You don't need to tighten any of the bolts fixed into the head to a great torque as it's aluminium which is a soft metal.

I thought the flange was held on with a stud screwed in to head and you just do up a nut?

sorry got that wrong, it is a bolt, just had a look.

Very tricky with the thread on the bolt.. I hd got a thread somewhere of about 2 years ago where the flange gasket was leaking & opened a can of worms. Had to drain the system, took off the Rad cowling, so I could get at it at the Corey angle & room to â€~tap’ it, cleaned out what I could of the damaged thread.. filled with liquid metal then left it overnight. Next day I used the gasket fixing â€~holes’ to mark the hole to drill, think it’s a 6mm hole, I think, lined it up & drilled with a 3mm bit to give me a marker & central point. Then I had to â€~tap’ it with time, ease & patience!! Got a good thread! Renewed the flange at the time with a new gasket. Ok so got a good thread, fitted a helicoil & a new Stainless nut which can only be torqued up to 12nm. Replaced the the Rad cowling, flushed the system with water cleaner, refilled with VW G13… one of the trickiest jobs I’ve done! In between I did try reverse drill bits to get the dodgy bolt out but it failed..


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Deandubya said

Very tricky with the thread on the bolt.. I hd got a thread somewhere of about 2 years ago where the flange gasket was leaking & opened a can of worms. Had to drain the system, took off the Rad cowling, so I could get at it at the Corey angle & room to â€Â~tap’ it, cleaned out what I could of the damaged thread.. filled with liquid metal then left it overnight. Next day I used the gasket fixing â€Â~holes’ to mark the hole to drill, think it’s a 6mm hole, I think, lined it up & drilled with a 3mm bit to give me a marker & central point. Then I had to â€Â~tap’ it with time, ease & patience!! Got a good thread! Renewed the flange at the time with a new gasket. Ok so got a good thread, fitted a helicoil & a new Stainless nut which can only be torqued up to 12nm. Replaced the the Rad cowling, flushed the system with water cleaner, refilled with VW G13… one of the trickiest jobs I’ve done! In between I did try reverse drill bits to get the dodgy bolt out but it failed..


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It’s a fine pitch thread to I think.. x1


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