Sheared tandum pump bolt in engine block

D

davenportmb

Member
I was trying to fit a new Bosch tandem pump to my 1.4 TDI today. Unfortunately, I overtightened one of the two smaller M5 hex bolts holding the pump in place and it has sheared, leaving half the bolt in the block. Needless to say, I'm pretty upset. I've now got a car on my driveway which I can't fix or drive to a garage and, to be honest, I'm feeling a little bit out of my depth and very, very stupid.

Has anyone got any advice to get the offending item out of the block? If I take the tandem pump and cylinder flange off there's just enough space to fit a drill in the engine bay but - given the size of the hole, the tightness of the bay and my general lack of experience - I'm worried I'm going to damage the thread on the bolthole if I try and drill it out and then I'll really have something to be unhappy about!

Thanks in advance.
 
If the bolt sheared then the broken piece should come out just by turning it anti clockwise if it bottomed and this is why it sheered then that is an totally different ball game
Try turning the broken bolt end with the point of a scriber or similar pointed sharp pin
If it’s broken flush a stem Mel cutting wheel can be used to creat a screw driver slot in the end of the broken bolt
Best of luck
Paul


Sent from my iPhone using Tapatalk
 
  • Like
Reactions: fhl
No, I don't think it bottomed - I just overtorqued it: I thought it was 20nm for all four bolts when it's 20nm for the two larger bolts and 10nm for the smaller ones. I'm an idiot.

I've had enough today but I'll get back out there tomorrow, pull the tandem pump off and see if I can knock the broken section out.

Hilariously, when I pulled the old LUK tandem pump off, there was no gasket on it. No wonder it was pissing oil everywhere! Who the hell had this car before me and who was their mechanic?!
 
If you're lucky there may be a bit protruding and you'll get molegrips on it, take your time and don't panic if its not bottomed it will move with patience.
 
As people have said it's unlikely it bottomed out and as it sheared on tightening rather than loosening you have a good chance of unscrewing it. As already suggested use a sharp punch to tap the broken end to slowly unscrew it or use a small cut-off wheel to make a screw driver slot. Best of luck getting it out!

Simon.
 
If you do in the end have to resort to drilling it out and access is restricted there is always an angle drill. From memory you need something like 100mm to get the chuck end in, assuming you can also get the body in, A useful at times addition to any DIY kit.

Andy

Edit. If you are worried about ruining the thread just thought it might be worth giving a stud/bolt extractor a go, cheap enough.
 
Last edited:
Managed to file a line into it with a half round file and get enough grip for a flathead screwdriver. I will never assume torque settings ever, ever again.

IMG_20190929_111623.jpg


Right, one new bolt and we should be back on the road. Thanks for all the advice, guys; this forum is invaluable.
 
davenportmb said:
No, I don't think it bottomed - I just overtorqued it: I thought it was 20nm for all four bolts when it's 20nm for the two larger bolts and 10nm for the smaller ones. I'm an idiot.

I've had enough today but I'll get back out there tomorrow, pull the tandem pump off and see if I can knock the broken section out.

Hilariously, when I pulled the old LUK tandem pump off, there was no gasket on it. No wonder it was pissing oil everywhere! Who the hell had this car before me and who was their mechanic?!
Click to expand...

There are two types of tandem pump, one has a separate metal gasket with ridges in it, the other has two O rings recessed into the surface of the pump. As far as I know there is no difference engine side. I can also reveal if you install a gasket on a pump with O rings it leaks .....
 
Ah, that explains it then. The LUK pump I pulled off had the o-rings on it and no gasket, however the Bosch one I put on had no o-rings but did have a gasket so I should be all good.

That's good to hear though, I was worried that I'd needlessly replaced the pump which could have been fixed with a gasket but it sounds like it was on its way out after all.
 
You must log in or register to reply here.
Back
Top