Leaking o-ring at water pump

rowan194 · 12-09-2013, 05:40 PM

Not sure if this is news (it is 10 years old after all) but I've never seen it referenced here before. It's the official procedure for adding a small section to the existing heater pipe assembly to allow a better fit.

Has anyone done this exact procedure? Step 9 sounds easy, but I had trouble even loosening the 19mm bolt because there's about 1cm clearance to shove my offset ring spanner into. I can't imagine how I'd get it back on if I did manage to remove it. Also it's not clear how you're supposed to refit the pipe - where does it go behind the engine, and is it just a push fit?

For the moment I did it the "safe" way and partially removed the water pump (along with the fans, belt etc) in order to replace the o-ring. Pain in the backside but I didn't want to force the pipe. This is just a temp fix so I can use my car, I have the plug on order.

I'm wondering if the same type of plug can be used for the thermostat housing, which is also leaking. I ordered two, so I'll find out soon enough.

rowan194 · 12-09-2013, 06:05 PM

BTW, I still haven't been able to figure out why a large amount of coolant leaked out in the space of about an hour a couple of days ago... enough to overheat the trans and get the temp gauge heading towards the red. I initially thought the heater pipe had corroded past the o-ring, rendering the seal useless, then I thought maybe the pump let go, then I thought maybe it was a damaged o-ring. None of those. With a new o-ring and pipe and pump re-mated there's not a drip, leaving me wondering what went wrong, and if it's going to happen again...

Bill M · 14-09-2013, 10:24 AM

Hello Rowan194,
are you referring to Ford PN. BA18N318S / AU8K540A ?
It is a centring ferrule the positions the tube inlet into the water pump port at the back of the pump and prevents the O ring from being misaligned and leaking. For 2003 and earlier BA AU falcons.
I was unaware of its existence and like you have not seen a reference to it here. I made up an alignment jig to centre the o ring and have no leaks in my last pump replacement.
cheers
Bill.

rowan194 · 14-09-2013, 02:43 PM

Quote:

Originally Posted by Bill M

Hello Rowan194,
are you referring to Ford PN. BA18N318S / AU8K540A ?

Yes. The OP seems a little disjointed because it refers to a service bulletin which the mod says I cannot post.

This auction shows a few pics of what the ferrule looks like mated to the pipe. It has changed slightly since I purchased it a few days ago, it now seems to include the o-ring and it also mentions part numbers (I thought this fix was aftermarket - could have just bought it down the road at Bayford spares if I'd known they were official Ford). Note that the description says they will send you a PDF of the bulletin on request.

http://cgi.ebay.com.au/ws/eBayISAPI....m=121174797142

Even though I'm not permitted to link to the content of the bulletin we really need to get the word out about part number BA 18N318 S / AU 8K540 A !!! It's such a common fault that I'm surprised it has not been mentioned more here.

I purchased two as I'm going to try to fit one to the thermo housing, which is also leaking.

mik · 14-09-2013, 02:21 PM

Thats interesting, didn't know about the aligning tool , looking at the housing on my last water pump there seems to be no particular area in which the the o ring actually sits, its just a reamed out housing, obviously a bit of side loading on the o ring end of the pipe could make the o ring more prone to leak.
The procedure for changing the water pump annoyed me so loosened the tube retaining bolt off and i cut about three quarters of an inch out of the tube with a thumb pipe cutter in an easy to get at area to make the job a quickie in the future should the o ring decide to leak,
i got a bit of from memory......... three quarter inch heater hose over the two bits of pipe and secured it with hose clamps, in future, i drop the coolant and loosen the clamps slide the hose back, remove the pipe from water pump end and fit a new o ring clean the the water pump housing put a very light smear of good silicon in the housing and reassemble, and add coolant, much nicer than trying to undo the bolt on the tube, or removing water pumps.
my only real concern doing it this way was the exhaust might bugger the hose eventually, so i cut a bit of old heat shield and squeezed it around the hose, when this water pump bites the dust i have another mod in mind that will be better i think, i will do away with the o ring all together by tapping a thread in the water pump and installing a brass fitting....... thats the plan anyway.
good luck with your o ring.

Bill M · 15-09-2013, 08:32 AM

Thanks for the thread, that is a great help for AU owners. I forgot, I did have an issue with the seal when I initially installed the Repco pump, after about 3 months there was a leak which is when I found the O ring with a flattened side. I then made up the jig to centre the pipe into the pump port.
cheers
Bill.

peterljohnson55 · 15-09-2013, 04:03 PM

This post considers this problem... about fitting a hose barb fitting into the water pump body, and short length of hose...
http://www.fordforums.com.au/showthread.php?t=11368212

As does this one...
http://www.fordforums.com.au/showthread.php?t=11367396

rowan194 · 22-09-2013, 06:00 PM

I haven't had a chance to try fitting the spigots yet - limited daylight and a bolt that's stuck fast, rounding off the head - but I did manage to get a shot of the old o-ring today.

Bit hard to tell, but you can see that it's thinner around the middle-upper left, and rather fat near the bottom right. I presume if it was centered properly it wouldn't have been pinched like this.

mik · 26-09-2013, 10:51 PM

yep, that is a fair comment, even if you center it i would give housing a good wipe with metho and then a light smear of quality silicon gasket in there, it seems to last the life of the water pump(touch wood).

bloggs24 · 10-10-2013, 01:48 PM

I bought this fix a couple weeks back, took 15 minutes to do and no leaking water pump

Price + Postage is a bit steep though but oh well.

peterljohnson55 · 11-10-2013, 02:12 AM

This is a very worthwhile google search, using the following criteria ...

BA18N318S AU8K540A pdf

peterljohnson55 · 11-10-2013, 09:50 AM

I question whether the problem results from a centring issue on installation or from the pipe putting a horizontal force onto the o-ring after installation. Either way it isn't a good look. The fix that rowan94 and others have highlighted, using FORD's solution (new plug and o'ring, per FORD Technical Service Bulletin Number 71R/03) will both align the pipe during installation and keep it central within the water pump's port during its life.