Bringing a 740 back to life

[Challo]

Originally Posted by Laird Scooby

That's a nuisance Chris! Just to be sure, it's not coming from the seal between the pump and head is it?

If not and you're convinced it's the pump shaft seals (only other place it can leak except the gasket which would be obvious) then it's a new pump - go for an SKF one, they're a bit dearer than most but you don't want to have to do the job again in a few months!

Is there a way to test the seal between the pump and the head? Access is limited to look underneath for a good angle.

It’s defo dripping directly underneath the pump as far as I can see.

https://www.partsforvolvosonline.com...843c3adb93820e

[Laird Scooby]

Originally Posted by Challo

Is there a way to test the seal between the pump and the head? Access is limited to look underneath for a good angle.

It’s defo dripping directly underneath the pump as far as I can see.

https://www.partsforvolvosonline.com...843c3adb93820e

Looking at this pic from further up the thread, i'd say the leak isn't between the pump and the head.



If you can run the engine up a bit, not so it's hot or you might end up burning yourself on the exhaust manifold but just so the temp guage has started to move then switch off, that should be enough warmth to provoke the leak. If you can contort your fingers to fit behind the w/pump pulley and feel in the bottom of it, if it's damp then it's almost certainly the pump.

That looks like a "Professional Partsd Sweden" pump you've linked to - i'll let the others tell you about those!

https://www.ebay.co.uk/itm/194248975127

That links to an SKF pump BUT in the listing they suggest it may be SKF, Meyle or Febi in which case, save your money and buy :

https://www.ebay.co.uk/itm/255027024367

I've never had a problem with First Line and as they're now part of Febi-Bilstein, you may as well get the same animal but cheaper!

When fitting, clean the underside of the head where the seal fits, smear silicone grease on the seal, the "O" ring that goes on the metal pipe that enters from behind (ooo-err missus! ) and silicone grease on the gasket (both sides) and get the pump loosely in place with the bolts finger tight.

Can't remember which of my 740s i had to renew the seal between the head and pump but one of them, when i did it i used a scissor jack to push the pump up from underneath to ensure the seal was compressed.

[Challo]

Defiantly damp underneath the pump so will get that one ordered and fitted.

Can you explain the scissor jack point? I’m a little lost.

[Laird Scooby]

Originally Posted by Challo

Defiantly damp underneath the pump so will get that one ordered and fitted.

Can you explain the scissor jack point? I’m a little lost.

When you fit a water pump on a redblock, you need to apply upwards pressure from underneath then tighten the nuts/bolts that secure the pump Chris. This is to ensure the seal between the pump and head does its job and now the advice in my previous post about the silicone grease on the gasket and the seal and leaving the fasteners loose (not quite finger tight) should make a lot more sense.

It's pretty tricky to push up evenly and tighten the fasteners at the same time unless you happen to be an octopus with the reach of Guy the Gorilla so i devised a cheat method of using a scissor jack underneath the water pump with a block of wood in between to minimise damage and keep the pressure even and constant while the fasteners were secured.

No doubt Volvo have a special tool that makes it easy like i'm sure Ikea have a special tool to make fitting sofa covers easy. I'm sure ex-Volvo designers formed Ikea to take a simple idea and complicate the bejesus out of it or "Volvo it" so they could take sadistic satisfaction of terrorising the part of the population that hadn't bought and self-maintained a Volvo!

[bob12]

I have always found that a heafty long handled screw driver placed judiciously as a lever is suffficient to ensure the top seal fits snugly as you tighten up the securing nuts. It is essential that the mating surfaces are clean and that the top seal area and groove on the cylinderhead is 101+% clean. I have been known to give the pump block gasket an ultra light finger wipe of good gasket sealant.

I always disconnect the back pipe from its holding bracket on the block before fitting a new pump. This allows more wiggle room and you can finally check it is fully pressed in and tighten up the bracket once the top gasket/and pump has been secured.

Bob

[Challo]

Thanks Both. Pump has been ordered so should be able to get it stripped down on the weekend and should give me a better idea of what I need to do.

[Challo]

Just been reviewing how to video's on the waterpump replacement, everything looks straightforward.

Only question relates to the switching of studs between the old pump and the new? Is there an easy way to do it? I dont have a vice or anything to hold the old pump in.

[360beast]

Put a nut on the stud and then put another one on top of it. Use two spanners or a spanner and a socket, you need to undo the bottom nut and tighten the top one so they compress together. Then use the spanner to undo the bottom nut and it should extract the stud, leave the nuts on and use the top one to fit the stud to the new pump, alternatively you can get some short bolts and use those instead.

[Ian21401]

Luke’s description of using two nuts to remove a stud is standard practice, but I don’t understand your comment about removing studs from the old pump to the new pump as there are none to remove.
IIRC there are two studs in the engine block which locate through the oval holes on the pump body. (They are the ones that you locate the pump onto prior to levering it up) At the same time, having previously slackened the rigid heater pipe to engine block bracket as suggested by Bob, line up and insert the rigid heater pipe ( with new “O” ring ) into the hole at the back of the pump body. ( but don’t tighten it yet.) Then once the pump is levered up into position the other three holes line up with the tapped holes in the block and the three bolts are inserted. Then tighten the two nuts and the three bolts and then tighten the rigid heater return pipe into the back of the pump body and then tighten it’s bracket.

[360beast]

Originally Posted by Ian21401

Luke’s description of using two nuts to remove a stud is standard practice, but I don’t understand your comment about removing studs from the old pump to the new pump as there are none to remove.
IIRC there are two studs in the engine block which locate through the oval holes on the pump body. (They are the ones that you locate the pump onto prior to levering it up) At the same time, having previously slackened the rigid heater pipe to engine block bracket as suggested by Bob, line up and insert the rigid heater pipe ( with new “O” ring ) into the hole at the back of the pump body. ( but don’t tighten it yet.) Then once the pump is levered up into position the other three holes line up with the tapped holes in the block and the three bolts are inserted. Then tighten the two nuts and the three bolts and then tighten the rigid heater return pipe into the back of the pump body and then tighten it’s bracket.

I believe he is talking about the four studs on the front of the pump to hold the pulley on to the pump.