Urgent - 90 degree coolant fitting on head - how to tighten

m1tch · July 17, 2020, 17:17

Hi all,

Just rebuilding the engine hopefully ready to go back in tomorrow or Sunday, there is a 90 degree heater hose fitting on the back of the cylinder head.

I am unable to fully tighten it down with the nozzle pointing the right way - anyone got any idea of how its meant to be installed to allow it to be correct or shall I use some sealant/PTFE tape etc?

I am unable to get to this part after the engine is in so its a one shot deal - if I get it wrong the engine has to come out again.

Thanks in advance!

Carolyn · July 17, 2020, 17:44

That's a bugger! I've never removed one from a head as that was always a worry. Is it bottoming out in the head, or is it running out of thread? Either way, the fitting could be carefully modified to clock properly. You certainly don't want a leak in that spot.

PTFE tape, heavily applied might get you there, otherwise I'd be looking at a thread sealant that sets hard. I've had some stuff like that, which we used on hydraulic fittings and it worked.

m1tch · July 17, 2020, 18:01

Quote from: Carolyn on July 17, 2020, 17:44That's a bugger! I've never removed one from a head as that was always a worry. Is it bottoming out in the head, or is it running out of thread? Either way, the fitting could be carefully modified to clock properly. You certainly don't want a leak in that spot.

PTFE tape, heavily applied might get you there, otherwise I'd be looking at a thread sealant that sets hard. I've had some stuff like that, which we used on hydraulic fittings and it worked.

I am picking up both PTFE tape and thread sealer stuff, its snug at around 90 degree past where it needs to be so its mostly sealed. Think the PTFE tape might act like a mini spacer meaning it might stop perfectly - another option might be to put a small washer inside the head the same ID as the pipe fitting - if there is a step, to act as a spacer.

Think I might go down the PTFE route and might also perhaps see if I can run a few copper crush washers between the head and the fitting as an extra belt and braces option.

m1tch · July 17, 2020, 19:14

Currently hand filing down some copper washers

going to get some PTFE tape tomorrow as well.

m1tch · July 17, 2020, 20:16

Also looks to be a taper thread I think - really stressed!

jvanzyl · July 17, 2020, 20:26

If it's tapered and it's not going down all the way (my assumption) then surely there must be something in the bottom of the hole that is blocking it? The only other possibility (in my small world) is that when they put it in originally, the set it with what Carolyn said - some kind of solid cement sealant..

Carolyn · July 17, 2020, 20:30

I'm sure it can be sorted. Stress not!

If you can't get a result with PTFE or setting thread sealant, you could bring the engine to our workshop - a pain I know, but with all the kit we have and David's experience, you'll get your result.

m1tch · July 17, 2020, 22:42

The thread in the head just goes directly into the water jacket. I will see if sealing it with the tape and some crush washers/rubber seals/sealant works. Think I might perhaps connect it all up and run a hose into it and block up one end to check for leaks.

Another option is to look to fit a banjo of some sort as it just needs to flow water from the head to the oil warmer etc.

Plan was to finish sorting wiring and plumbing tomorrow, plus flywheel and clutch and lift it back into the car on Sunday.