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H22a t-stat housing removal - water pump pipe?
Posted: Sun May 19, 2013 9:58 pm
by Angus
I need to take my thermostat housing off - the bit that attaches to the head, not just the t-stat cover. This is because I have a sheared bolt that holds the cover on, which is letting a tiny leak of coolant out (looks like the source of my previously mentioned constantly dropping coolant level) - so I need to take the whole thing off to drill it out.
I see three bolts attaching to the head, that bit's OK.
But ... can anyone advise how the pipe that goes to the water pump connects to the bottom of the housing? Does it just push on? Can't see any bolts anywhere near it on any diagrams ...
Any other relevant advice also greatly appreciated!

Posted: Sun May 19, 2013 10:21 pm
by Vtecmec
Yes, it 's just pushed on, with a big rubber o ring to seal it.
Posted: Sun May 19, 2013 10:56 pm
by Angus
Great! Thanks.
Job for next weekend, then. That and cam seal and rocker cover gasket ... I
will stop my car leaking stuff.
Posted: Mon May 20, 2013 10:26 am
by wurlycorner
Excellent determination!
Glad you've found the source of the coolant leak...
Posted: Thu May 23, 2013 11:00 am
by Angus
Just for future interest, here's one currently on fleabay showing the relevant end ...
http://www.ebay.co.uk/itm/Honda-Prelude ... 177wt_1170
Posted: Thu May 23, 2013 11:08 am
by wurlycorner
Careful - that one won't be the same as all of ours though, because it's off one of those rare beasties;
Honda Prelude TYPE R BB1 MK4 92-96 2.2 VTEC

Posted: Fri Jun 14, 2013 8:13 pm
by Angus
Just a finisher for the thread ... for future reference.
Stat housing takes a bit of a tug to remove from the water pump pipe, but does indeed just pull off.
I noticed after putting it back together that it was still wet underneath where it joins that pipe - but after a bit of careful observation I noticed it was actually the small-bore hose on top of the stat housing that wasn't sealing properly anymore (looked like it'd never been removed, and had probably expanded that little bit to keep pace with corrosion of the metal over the years - scrape corrosion off, ID of hose now that fraction too big).
One nice tight Jubliee clip plus a mental note to replace the hose at some point, and coolant seems to be non-leaking now.
Lovely and clean down that side of the head now, what with bust heater hose cleanup, VTEC gasket and cam seal too recently!
Re: H22a t-stat housing removal - water pump pipe?
Posted: Mon Oct 05, 2015 3:29 pm
by bargoat_0314
Not to bring something back from the dead, but I have encountered a similar issue. I had a thermostat housing bolt broke off in the head. I was able to get the bolt out of the head, but I noticed a leak coming from the tube going to the water pump where it seats in the thermostat housing. the rubber ring looks fine but it seats kind of sloppy.
Do you guys happen to know a part number or any helpful info towards this? its a 96 h22a with 40k miles..
All help is very much appreciated

Posted: Mon Oct 05, 2015 3:38 pm
by Merlin
Number 24 on the diagram - Part No 91314-PR7-A00 £3.60

Posted: Tue Oct 06, 2015 1:05 pm
by bargoat_0314
YOU ARE THE BEST MAN!!!!
greatly appreciated brother. do you have the part number sheet for all the numbered parts in the diagram for my future reference?
thank you so much!
