does anyone know what size the water pump bolts are? I sheared one

Hi guys
Just giving the old girl a jolly good service, noticed the fan had slight play so I decided to do the pump and new belt, but my mate helping me sheared the last bottom right 11mm bolt head off, we got the pump off and luckily a bit was stiching out, so a few people had a go with stilsons etc but it was no good so I went to halfrauds and got a bolt extractor cheaper than ebay for some reason for the same one and I didn't have to wait 3 years for it! anyway I heated the bolt gently then let it cool and bingo the extractor worked nicely, however now I have no bolt to put back in and nobody does them on ebay,
does anyone know what size I need so I can google it and find somewhere that does them, they only have thread at the end not all the way up,
hope someone can help me please

richieb said:

Hi guys
Just giving the old girl a jolly good service, noticed the fan had slight play so I decided to do the pump and new belt, but my mate helping me sheared the last bottom right 11mm bolt head off, we got the pump off and luckily a bit was stiching out, so a few people had a go with stilsons etc but it was no good so I went to halfrauds and got a bolt extractor cheaper than ebay for some reason for the same one and I didn't have to wait 3 years for it! anyway I heated the bolt gently then let it cool and bingo the extractor worked nicely, however now I have no bolt to put back in and nobody does them on ebay,
does anyone know what size I need so I can google it and find somewhere that does them, they only have thread at the end not all the way up,
hope someone can help me please

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What car? If they have an 11mm 7/16 af spanner size they are likely to be 1/4 unf. Or unc if going into alloy. 6mm would be 10mm spanner size. Measure thickness of casting and add that to the bit of thread you have to get shank length. If you fit a 6mm bolt in a 1/4 unf hole you WILL strip the thread in the hole. If bolt has a ring on head it is UNF or UNC. Unified thread. Strike marks on head will tell you it's tensile strength. Three good. Five best HT. If i remember right.

That saves me trolling through the Zeus Book or blowing the dust of my copy of 'The Machinists Handbook'...

BTW, RichieB has a V8 P38!!

Saint.V8 said:

That saves me trolling through the Zeus Book or blowing the dust of my copy of 'The Machinists Handbook'...

BTW, RichieB has a V8 P38!!

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Think most bolts on the V8 are UN series. They certainly used to be. Maybe a bit of metric **** has crept in over the years. The head studs are 7/16 UNF 5/8 spanner, not the 16 mm people use to round the nuts off with. In metric think a 11mm spanner size would be a 7mm bolt and they are like hens teeth. Far more likely to be 1/4 UN 7/16 spanner size. Oft mistaken for 11mm.

PS. ZEUS book could not live without them at one time.

I managed to find one in my mates greenhouse on the floor, it was same length etc just had a 10mm head instead of 11mm, got it all back together accept the fan,, oh my god it's driving me mad I thought i had it on at 1 point but it was cross threaded and I had a job to get it back off, now the thread looks a bit crap on the end and I can't get the sodding thing on, has anyone ever ran a p38 without the viscus fan? do the electric ones cool it if it gets hot, seems silly having 3 fans! surely I only need the viscus if stuck in traffic??
nice to see you guys again by the way, it's been a while!!
I got some nice new ht leads but no way I can get to those as the lpg kit's all in the way, shame as I was hoping to do those as she runs a bit lumpy cold,

Some people just don't listen.

richieb said:

I managed to find one in my mates greenhouse on the floor, it was same length etc just had a 10mm head instead of 11mm, got it all back together accept the fan,, oh my god it's driving me mad I thought i had it on at 1 point but it was cross threaded and I had a job to get it back off, now the thread looks a bit crap on the end and I can't get the sodding thing on, has anyone ever ran a p38 without the viscus fan? do the electric ones cool it if it gets hot, seems silly having 3 fans! surely I only need the viscus if stuck in traffic??
nice to see you guys again by the way, it's been a while!!
I got some nice new ht leads but no way I can get to those as the lpg kit's all in the way, shame as I was hoping to do those as she runs a bit lumpy cold,

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Nope they are there to aid cooling when the A/C is running.

The Diesels can get away with running the leccy fans for cooling, with the perpensity for the V8's to overheat, I don't think they would be adequate.

As the Wammer said above, don't try fitting a 10mm Spanner Size bolt (M6x1.00 Thread) as it will strip the original thread (1/4 UNF/C). I guess this is unfortunatly what has happened.

richieb said:

I managed to find one in my mates greenhouse on the floor, it was same length etc just had a 10mm head instead of 11mm, got it all back together accept the fan,, oh my god it's driving me mad I thought i had it on at 1 point but it was cross threaded and I had a job to get it back off, now the thread looks a bit crap on the end and I can't get the sodding thing on, has anyone ever ran a p38 without the viscus fan? do the electric ones cool it if it gets hot, seems silly having 3 fans! surely I only need the viscus if stuck in traffic??
nice to see you guys again by the way, it's been a while!!
I got some nice new ht leads but no way I can get to those as the lpg kit's all in the way, shame as I was hoping to do those as she runs a bit lumpy cold,

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You can normally do the ht's with an LPG kit in but be prepared for skinless knuckles, fingers, etc. It's fiddly and tight (oh-er!) but I've (well me and my mate) done two sets.

Do one lead at a time so you know what came from where. Not teaching anyone to suck eggs, but it's an easy mistake to make!

Or find a mechanic with small hands!

Saint.V8 said:

Nope they are there to aid cooling when the A/C is running.

The Diesels can get away with running the leccy fans for cooling, with the perpensity for the V8's to overheat, I don't think they would be adequate.

As the Wammer said above, don't try fitting a 10mm Spanner Size bolt (M6x1.00 Thread) as it will strip the original thread (1/4 UNF/C). I guess this is unfortunatly what has happened.

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I didn't understand all the stuff about the bolt sizes!! anyway the 10mm bolt went in fine, the thread etc was all the same it was only the head that was different, it's only the fan that got cross threaded and I can't get on, everything else is back together, I didn't think the fan would be so awkward but it is!!!

Topboy said:

You can normally do the ht's with an LPG kit in but be prepared for skinless knuckles, fingers, etc. It's fiddly and tight (oh-er!) but I've (well me and my mate) done two sets.

Do one lead at a time so you know what came from where. Not teaching anyone to suck eggs, but it's an easy mistake to make!

Or find a mechanic with small hands!

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think I'm gonna have to pay someone which I hate to do as I can't get my foot in there with all these water pipes going accross from the lpg system (I have no idea why it's connected to the water pipes!? the gas goes into these 2 silver things that have water pipes going in as well, but the pipes go right above the coils which isn't handy)
I hate paying people to do such a job but my mate had a look and turned his nose up too so looks like a garage job,, just hope it runs better after and gives me a bit more than 11mpg!
still have a weird thing going on with the eas, every time a door shuts it lets some air out!! it goes down to the stops almost over night but there are no leaks as If I disconnect the battery is does not move!!! so the car is doing it not a leak,,

richieb said:

I didn't understand all the stuff about the bolt sizes!! anyway the 10mm bolt went in fine, the thread etc was all the same it was only the head that was different, it's only the fan that got cross threaded and I can't get on, everything else is back together, I didn't think the fan would be so awkward but it is!!!

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Generally 6mm bolts have a head size of 10mm. 10mm spanner size. 1/4" UNF bolts have a head size of 7/16" or 11.1125mm. 7/16 or 11mm spanner size. The thread pitch is very simular. A 6mm bolt is 6mm in diameter, a 1/4" UNF bolt is 1/4" inch or 6.35mm in diameter. You can easily screw a 6mm bolt into a 1/4" inch threaded hole, but you stand a good chance of stripping the internal thread. You cannot screw a 1/4" bolt into a 6mm threaded hole. Unless the waterpump bolts are a special size for the purpose. It is odds on the bolts you took out were 1/4"UNF. The one you found on your mates floor with a 10mm head will odds on be 6mm diameter. ALL bolts and nuts on the V8 engine used to be Unified threads. It's an American designed engine. Unless they have been changed over the years which i suppose is possible.

wammers said:

Generally 6mm bolts have a head size of 10mm. 10mm spanner size. 1/4" UNF bolts have a head size of 7/16" or 11.1125mm. 7/16 or 11mm spanner size. The thread pitch is very simular. A 6mm bolt is 6mm in diameter, a 1/4" UNF bolt is 1/4" inch or 6.35mm in diameter. You can easily screw a 6mm bolt into a 1/4" inch threaded hole, but you stand a good chance of stripping the internal thread. You cannot screw a 1/4" bolt into a 6mm threaded hole. Unless the waterpump bolts are a special size for the purpose. It is odds on the bolts you took out were 1/4"UNF. The one you found on your mates floor with a 10mm head will odds on be 6mm diameter. ALL bolts and nuts on the V8 engine used to be Unified threads. It's an American designed engine. Unless they have been changed over the years which i suppose is possible.

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I measured the bolt width with my caliper and it said 8mm and after some research I did an 8mm bolt is an m8, the reason I thought these were metric bolts were I watched a video on youtube of someone changing a pump and he said 3 are 11mm and the rest 10mm, I had no idea where to get the bolts as there were none on ebay and the pumps don't come with bolts, silly really as these come out very sooty and crappy, hopefully what I did was good enough and keep her going for another 100k!!:tea:

richieb said:

I measured the bolt width with my caliper and it said 8mm and after some research I did an 8mm bolt is an m8, the reason I thought these were metric bolts were I watched a video on youtube of someone changing a pump and he said 3 are 11mm and the rest 10mm, I had no idea where to get the bolts as there were none on ebay and the pumps don't come with bolts, silly really as these come out very sooty and crappy, hopefully what I did was good enough and keep her going for another 100k!!:tea:

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OK they must be special fitment. 8mm bolts will usually be 13mm spanner size.

The LPG is piped into the coolant system to use the warm engine coolant to help vapourise the Liquid Gas, makes the expansion more efficent.

You do realise the fan is an anticlockwise thread don't you

defender300td1 said:

You do realise the fan is an anticlockwise thread don't you

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That's the fan hub. He is talking the bolts that hold the fan to the hub.

Mmm not too sure warmers-first thread says bottom right you would state that on an item that's fixed not that spins around and later on he says can't get fan on you don't fix hub on then fan that's a bit long winded isn't it you might be right tho he might take fan of hub then hub of water pump if backwards plus thread says snapped water pump bolt I'm starting to think your suffering from alzsimers however spelt

No It was the FAN the large nut onto front of pump I couldn't get on, it is a normal thread on the v8 not left handed, managed to get it on today with a mates help, and also did the plugs and leads, just managed to work around the lpg


that's interesting saint v8,, you sure you don't want to come and fix my lpg!!!!

defender300td1 said:

Mmm not too sure warmers-first thread says bottom right you would state that on an item that's fixed not that spins around and later on he says can't get fan on you don't fix hub on then fan that's a bit long winded isn't it you might be right tho he might take fan of hub then hub of water pump if backwards plus thread says snapped water pump bolt I'm starting to think your suffering from alzsimers however spelt

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Bottom R/H is obviously bottom R/H bolt on water pump to block. He later says he crossed a bolt into fan hub. Why he took those out and did not just remove fan and hub i don't know i am not psychic. Maybe he did not have a spanner for the hub. Why would i be suffering from alzheimers, and that's how it's spelt? Fans always undo in the direction they rotate. The V8 is a R/H thread the diesel is a L/H thread.

the fan is a 36mm right hand thread, took that off then pulley then pump, can't get pulley off the old pump unless the fan is taken off so cant remove it all as the thread is on the pump for fan not the pulley, sorry it might just be the way I put it, you're not mad wammers don't worry!