Alfa Romeo Owners Club of Australia Forum

Technical => Vintage and Classic Registers (all cars Pre 105 Series) => Topic started by: 156and33 on September 17, 2017, 08:21:42 AM

Title: 156 2.0 JTS rigid coolant pipe leak
Post by: 156and33 on September 17, 2017, 08:21:42 AM
Hello

I have had two goes at fitting a new front rigid coolant pipe on my JTS and am not getting it to seal. The pipe is new and the seal is not damaged. I have cleaned the head and removed all the crusty residue built up from the previous leak. There is some minor discolouration of the mating surface which appears to be corrosion. My second attempt yesterday used a small amount of aviation sealant on the o-ring to try and fill any defects in the mating surface. I have not torqued the bolts just snugged up firmly. Still leaks.

Feeling knackered from replacing the alternator as well yesterday. Would really like a foolproof (yes, I must be a fool to keep this car) solution for the next go.

How about removing the silicone seal and using RTV to form a gasket in place?

Thanks
Title: Re: 156 2.0 JTS rigid coolant pipe leak
Post by: bonno on September 17, 2017, 08:45:15 AM
Hi 156and33
Are you referring to the Air Conditioner rigid pipes, rather than the coolant tank rubber hoses. If A/C pipes you will need to take it to A/C specialist to replace/repair, evacuate and regas.
Regards
bonno 
Title: Re: 156 2.0 JTS rigid coolant pipe leak
Post by: 156and33 on September 17, 2017, 09:43:47 AM
Engine coolant not a/c.
Title: Re: 156 2.0 JTS rigid coolant pipe leak
Post by: bonno on September 17, 2017, 10:12:24 AM
In that case, the mating surface need to be absolutely clean and without imperfections for it to effectively seal.
Title: Re: 156 2.0 JTS rigid coolant pipe leak
Post by: Citroƫnbender on September 17, 2017, 10:40:01 AM
Is it possible the bolts bottom out before sufficiently compressing the joint?

Does it only weep under hot pressure?
Title: Re: 156 2.0 JTS rigid coolant pipe leak
Post by: 156and33 on September 17, 2017, 12:45:21 PM
Hey, that is a posbility I had not thought about and it could well be the problem  they could have water in them. Thanks
Title: Re: 156 2.0 JTS rigid coolant pipe leak
Post by: Mick A on September 20, 2017, 12:10:08 AM
There is a metal bracket for the heat exchanger piping to the oil filter housing. This must sit over the plastic manifold mount where they both sit on a stud and are secured with a 13mm nut.

If you have it the other way around, the plastic manifold will not sit flush against the sealing surface on the head. It will appear flush, but it will never seal properly due to the slight angle.

Cheers.

Mick.
Title: Re: 156 2.0 JTS rigid coolant pipe leak
Post by: 156and33 on September 22, 2017, 05:37:37 AM
Not really sure what you are describing on this vehicle.  Will check next weekend when I try and fix it again.
Title: Re: 156 2.0 JTS rigid coolant pipe leak
Post by: 156and33 on October 01, 2017, 06:54:08 PM
Success!
Thanks Mick A, I did have the oil cooler pipe bracket on the wrong side of the rigid coolant pipe.  Also, blew out all the bolt holes for good measure. Nothing leaking on garage floor after drive and sitting for 5 hrs. If OK in morning I will replace underbody tray.  So car should be good to go with new cam cover gasket, coolant pipe and alternator.

Thanks everyone.
Title: Re: 156 2.0 JTS rigid coolant pipe leak
Post by: tidimel on July 14, 2020, 11:09:46 PM
Good afternoon for every one.

I've got the same problem as author of this topic.
I've read this, but i don't know wich metal bracket you mean guys.

Can i ask for a photo of proper mounting of this plastic water coolant pipe?
I bought new one, installed it over 6 months ago and now, when it's hot outside, when i turn off engine and it's cooling down i see water coolant drops going down from the left side of this pipe (staying in fron of it).
Sorry for my eng.

Rgrds Mat.
Title: Re: 156 2.0 JTS rigid coolant pipe leak
Post by: bonno on July 15, 2020, 10:51:38 AM
Hi Mat
Refer to Mick A post above regarding bracket and also did you replace the gasket #7 as well when new coolant pipe fitted. For your reference I have attached photo of IPB of the cooling system.
Title: Re: 156 2.0 JTS rigid coolant pipe leak
Post by: tidimel on July 15, 2020, 03:38:03 PM
Bonno, of course plastic pipe was changed with new one gasket.
I didn't do it by myself, my mechanic did that;)

Yesterday I checked the fixing screws from the gasket side.
I think I have to buy a new one gasket, reserve a few hours, dissemble this plastic pipe and perfectly clean the connection between engine and gasket. If it doesn't help, I'll buy big pack of water coolant and put in in the trunk...

I see that is a common problem with this engine. In 1.8 Twin Spark there was an metal pipe, not plastic.

Thanks for picture.