Hissing noise from under carbs???

[Roy S]

OK the saga continues.......

Can't remove the inlet manifold now, the silicone is really working well (see new thread) >:(

But as I couln't get it off I thought I'd try tightening it up again but as suggested by FX4 and it worked. When I took the bolts off I noticed a couple were looser that others so it seems that the gaskets compress a little when left a few days. When I finally get this done I'll remember to check them after a week.

So anyway all tightened up but still a water leak under the manifold, checked where it leaked from before and all dry. Using a small mirror to look under the manifold I can see a slow drip from the water pump gasket. :D So on the one hand I'm pleased to have found this as well or I could have fitted the manifold with yet another set of gaskets and still had a leak. Only problem is I now can't get the inlet manifold off. I've posted another thread for this so if you are reading this and have a suggestion please put it in there to make it easier for others to find.

Might actually get this car going before pertol runs out........ :-/

[Roy S]

Manifold off (covered in other post) got the water pump off and the gasket does seem very soggy near where it was leaking (rear bolt).

The bolts seem to have seen better days, as it was late I've not tried to clean them up but I might pick up some replacements from the local tool/hardware shop if they don't look too good after a wire brush.

Have ordered up new gaskets, they come in three different sizes depending on the clearence so will need to check on this.

If old cars were easy everyone would have one....... ;)

[Roy S]

OK gaskets arrived (set of three) has anybody fitted these before and can help here. Understand you have to hand fit the bolts then measure the gap between pump cover and block and select from the three different thickness gaskets. Question is that if you need to are you ment to fit more than 1 gasket to get the correct clearance?

Have also bought some Hylomar blue to fit the pump and inlet manifold after the trouble I had removing it when I used the silicone gasket sealant.

[Roy S]

Cleaned up and re-fitted the waterpump, measured the clearance and allowed for the additional space of 10 thou as stated in the WS manual and fitted the 20 and 30 thou gaskets with blue Hylomar gasket sealant. Found this a real pain to use and fillting two gaskets didn't help maters either so when fitting the inlet manifold used the grey silicone I used before. All of this was over a few weeks as I had some other work to do and playtime on the car had been cancelled........
Anyway all back on but still a small weep from the same place on the manifold, loosened off all the bolts and re-tightened. It was better but a small bubble of water could been seen when pumping the top hose with the system full. Thoughts of setting fire the car ran through my mind at this point. As I wanted to see if there was any other damage to the engine decided to tightenend the bolts as far as I was happy to (steel into alloy...!) weep smaller so carried on. All back on and started the car up and as the engine warmed up no leak and system pressure held.

Ran the car today for a short 10 mile run with some rad cleaner in and will flush this all out tomorrow if I get time. Engine runs fine, revs freely and idles nice and smooth at about 600 RPM. Found an oil leak where it's dripping onto the RH exhuast and think it could be from the oil pressure switch, have given it a tighten so will wait and see.

So to sum up the hissing noise was the gasket giving up on the water pump and the final pressure in the system escaping. Will update this thread when I've managed to get it on a decent run to see if it's all OK.

[Andrew Lacey]

Nice to see your car up and running :)  You seem to have it sorted, All you need is the sunshine, do you know how to stop the sky's from leaking? ;D everytime we try to take the stag out the sky starts to leak, do you think this is just a stag problem?

Well! let us know how you get on when you go on a longer run. 

Tina :)

[Bryan]

Yes every time i open the garage, my sky leaks too. Definetly a design failing!

[Roy S]

OK so its not that easy..........

Ran the car for a few days (love that exhaust note) and noticed a small water leak but only when the car had been switched off for over an hour. When running the system was under pressure, no leaks (I could see) and the temp was steady at 1/4 up the scale, a little higher in traffic under stop start (did I mention that exhaust note?) but never any higher.

Kept an eye on the bottle and this seemed to drop by about an inch each day. Always in the morning a puddle of water was under the inlet manifold with as trickle line from somewhere up front.

With a small inspection mirror I could see that nothing was leaking from the manifold or the pipes and the water line heading forward was from near the water pump. I'd fitted new gaskets here with Hylomar blue on all surfaces and both sides of the gasket so was confident that this was not the cause. Nothing else for it but to remove the inlet manifold again.

With that out of the way I connected various pipes to enable me to get water into the engine to try and trace the leak, the head waterways were covered with tape. As it happened when cooled down I assumed when cold I could get it to do the same......wrong. Nothing at all. So can only assume that it the heating up and cooling down that lets it leak.

So armed with the WS manual and help from a friend we have now concluded that it must be from under the water pump as in the block you can see a brass bush with cut out slots that if the water seal on the pump has failed will allow water to pass down and drip out.

So that is what we decided tonight is the next step, looking in the book of parts you can get a repair kit so anyone done this before and can offer advice? Looking at it I'm thinking that I'll only replace the top part of the pump sort of bearing upwards. I can't see that the brass bush needs to come out as the two oil seals under this seem to be doing their job and the book does say this is a pain to remove. Above the bearing is a water seal and this is what I think is the cause of the leak. The shaft comes off the base of the pump and there is a gap between the pump housing and the rest of the engine block. Why it's made this way I don't know but at least if it leaks it can't get into the rest of the engine.

So, anyone offer any advice on the repair kit, do you need the special tool to get the 12 vane rotor off? Here we are the best weather so far this year and I'm working on the engine, still at least I can drive the MGB.

[wakaday]

Doh. If you had the lid off the pump off to change the gasket it would have been a great time to put a seal kit on the water pump.
Don't worry to much if you have a damp Vee when its all back together. You will see a hell of a lot of Stags like that. Once the heads have had a skim, it puts the inlet maniflod slightly out of alignment with its mountings and most heads have been skimmed by now.

[Roy S]

I know, but at the time the water pump gasket was the suspect and to be fair it practically fell off as the top cover was removed so it was the suspect for all of the leak. I've put a separate thread up for anyone who has changed a water pump before to find out what I can before I tackle the job next week, if you have any advice please place it there, thanks.