O series thermostat housing cap.

[Kilroy]

Hi all.

Am stuck for the above item(s). Bought some from eBay but they were totally useless and apparently only for show.
I have seen something that looks similar being sold for use on an Ambassador, and Earlpart have a listing for "radiator cap" Ital only - not sure if that might be the same thing.
Can anybody point me in the right direction.?

They are simply the cap and a full-width rubber seal - but they are under some pressure so need to be pretty serious.
The so-called replacements I have seen have nothing behind the rubber seal and the whole thing is an impossibly loose fit.
I may have to somehow recondition some I have on which the rubber has disintegrated, but new would be preferable.

Thanks,
Kilroy

[mickthefitter]

Kilroy, I've got no first hand experience but I've found this thread from a Marlin owner with a similar problem to you (in 2010). It might provide some clues.

Mick http://www.marlinownersclub.com/forum/s ... -Type-1700

[Kilroy]

Cheers for that.
I figure my best option is to invent a way of reconditioning some existing caps if I cannot find any suitable new ones.

It would help to have a part number...

[david painter]

Ebay item number 272174429499 Similar cap fitted to 4.2 series 2 & 3 Jag also used on Austin 1100/1300 range
Dave

[locost_bryan]

I presume you're referring to the cap on top of the thermostat housing (at the front of the head, by top radiator hose)? Should be a standard recovery type cap, compare an original one to what's on display at Supercheap (Tridon brand)? Tridon's catalogue doesn't list Marina or Princess, but gives the same cap part number for most other Austin, Morris, Jag and many Fords.

[mickthefitter]

I'm not sure what to look for because I've not got an O Series, but based on Dave's knowledge that it's the same cap for an Austin 1100, Kilroy's description that the one he got that was loose had a 'full width' rubber seal, and Bryan's photo that shows his cap with a brass rivet in the middle, this one might be some good

http://www.ebay.co.uk/itm/RADIATOR-CAP- ... SwCWFY8OhP

or a NOS apparently Unipart branded item here

http://www.ebay.co.uk/itm/AUSTIN-MORRIS ... 0005.m1851

[locost_bryan]

Marina 1.7 listed in Presco catalogue, "Rad Cap" and "Exp Tank", same part number ST1 as for Allegro, Ambassador, Maxi.
http://www.presco-radiator-caps.com/catalogue.pdf

QH cap on ebay

[Kilroy]

Cheers guys.
Yes Bryan - it is the thermostat housing cap.
The item linked by Mick appears to have the full width rubber and probably is the correct one.
The item linked by David looks more like several I have received from online purchases but does not do the job.
The local "Tridon TRC10" which should be a straight replacement for the original AC Delco RC10 simply isn't, and has a rubber coated disc which fails to seat with adequate pressure.