r cast iron sewage pump parts

Replacing water pump

Replacing water pump

Hi guys, I have to replace the water pump on my Astra H 2.0 Turbo - it just started sounding like a tractor and squirting coolant out. Luckily for me, the timing belt is on the to do list, so if you'll forgive the pun, the timing is just right. I've been checking the procedure and it all seems pretty straight forward, but I have one question. The TIS documentation states that the coolant pump sealing surfaces should be coated with white silicone grease, and there is no mention of silicone or such. 19.Before installing coolant pump, coat sealing surface with silicone grease (white) But an online video from a former vauxhall mechanic states to use gasket material as well as the rubber one supplied. He even goes on to describe how locktite 515 is pretty much the same as the one they used in the workshop. So I'm a little unsure - instinct says to put as much gasket material in there as possible Anyone know for sure?

Ant21

Having done my belt and water pump a couple of times. I use a small smear of gasket material on the water pump along side the supplied o-ring. Vauxhall once changed the belt and pump for me and did the same, but only smeared the gasket material on half of the pump... you can guess where it leaked from. So IMO, I would suggest using a small amount of gasket material with the pump. No need to cake it on as it'll just cause you more hassle. For info, this is the guide I always refer to when doing it as it's damn useful!

SkippyUpOver

So, I've stripped it down. Had to grind the tensioner bolt off after stripping the torx... But it seems the water pump was tearing itself apart - there were ball bearings and other little pins everywhere, and all of the vanes on the inside of the pump have been smashed off. This worries me a bit - I assume the bits have been sent out towards the radiator with the last of the coolant, before I shutdown the engine. I used the tap to drain the coolant, so I don't think any of the bits will have come out there, which means they must be somewhere in the system. Is there a procedure for making sure any bits like this are out? Or is it even likely to be a problem?

Ant21

Grinding off the tensioner torx... I don't envy you here, absolute pain of a job isn't it! Sounds like you caught the issue in time before the pump let go and took the belt with it. I don't believe on these blocks there are any block drains for the coolant, so I'd suggest doing what you can with a hose pipe & remove the upper / lower radiator hoses + thermostat to do what you can to remove any debris that may have travelled through the system. I doubt there will be much, but whilst it's in a state of 'bits' you may as well.

SkippyUpOver

So, I've got everything back together and i've aligned the marks on the 2 cams and the crankshaft pulley as per doc. Unfortunately when I was aligning to TDC before removing the belt, it slipped because of the broken water pipe and I was not able to mark the alignment as it was before. I mention this since, although the motor runs smoothly, it seems to sometimes not start as easily and has what might be some slight misfires. I have plenty of power if I put my foot down and get the turbo involved though. I was reading that a single tooth misalignment on the crank pulley might cause some such symptoms on some engines. Since I have 167 teeth, a single tooth would be about 0.59% change, so it might really not be too noticable. Of course it could be something totally unconnected with the timing... Today I took the timing covers off and took photos of all 3 marks. Where I am not sure, is on the crankshaftc - it sort of seems to depend on how I look at it as to whether it is aligned or not! If I run a line from the centre through the mark it lines up quite well. If the white mark is supposed to be vertically over the outer mark then it is out... Anyone know? Thanks, Nick

SkippyUpOver

OK, so I think I have found what I need

Ant21

Yes I'd say you're one tooth out on the crank.

SkippyUpOver

Ant21 thanks for the input, without it, given how far out it looks below, I probably would not have tried... OK, so I finally got around to doing this - as you can tell, the car ran well enough that this was not a priority. To be honest, if I did not know about the timing belt change I would probably just ignore the symtoms, or go looking at the throttle body or something equally expensive So now it looks like this - and seems to run perfectly... optically, the crank markings definitely do not seem to be aligned. I find this a little unsettling but it definitely runs better than before... For those of you that have as much problems as I did actually getting the tensioner installed while maintaining the tooth alignment, check out this video on how to easily move the belt one tooth in either direction - without even releasing the tension... It works, needs a "tool" that we all already have, takes about 30 seconds and saved me countless grey hairs Cheers all

Ant21

Oh that’s interesting. You look even further out on your timing marks now! surprised it runs better to be honest. thinking out loud it might be the clocking of your water pump causing it to be slightly out of line as they’re not central to the pump body.