Busted bolt during fuel injection pump seals repair (pic)

jesiah

Member
Joined
Mar 7, 2018
Location
Portland
TDI
'03 Jetta Wagon
2003, MK4 ALH TDI... Was putting the pump back together after replacing the leaky seals. Everything went super smooth, then this last bolt snapped as I was tightening it. Oops. It's the driver-side and front bolt on the side.
It's the one sticking out in the picture here



In this next picture, I'm holding the bolt on the outside of the injection pump to see how deep inside the break is. It appears to be before the two pieces of the injection pump body join. Which shouldd mean the broken off bit inside might still be doing its job holding them together?


http://i.imgur.com/RXsmKCd.jpg
The broken bit head just spins freely now and can't be tightened.

Thoughts? Do I start it up and see what happens? Have it towed straight to a junk yard?

If the broken bit inside is not holding the two parts of the IP together, but all the other bolts are, is it just going to leak everywhere anyway? Any risk to continuing with finishing the repair and them driving 1,000 miles home tomorrow, from LA to Portland?

Thank you for your wise input! This board has been incredible.
 
Last edited:

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
How'd that happen?

If there's no other issue other than this then run it and see how well it holds fuel (pressure). If it doesn't spray fuel all over (clearly a bad thing) then you might be OK to limp it.
 

dweisel

Top Post Dawg
Joined
Jul 28, 2006
Location
Wheeling, West Virginia
TDI
dweisel isn't diesel anymore!
Only thought I have would be to buy the proper sized bolt that is threaded all the way and just short of the depth of the broken bolt and hope it MIGHT catch a thread or two. Probably wishful thinking as the bolt probably broke right at where the threads start.

The long term fix is probably changing out the ip for another one, because getting the broken bolt out will require disassembly of the ip. Not a lot of people are capable of taking an ip apart and reassembling it (including myself). There are detailed instructions online if you decide to go that route.

dweisel
 

whitedog

Veteran Member
Joined
Jul 12, 2004
Location
Bend, Oregon
TDI
2004 Jetta that I fill by myself
The stretch of the bolt between the threads and the underside of the head is what provides the clamping force so, no. The threaded portion is not holding anything together. If it we're me, I would get a left handed drill bit in my right angle drill and try to catch the end of the bolt and HOPEFULLY it would turn it out. Nothing to lose by trying this because the next step is to remove the pump, clamp it straight up and down, rotate the pump so it's on the bottom of the camplate and remove the head. It looks like the bolt is still sticking out a bit, so from there, it should be easy.
 

AndyBees

Top Post Dawg
Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
Considering one of your options is, "Have it towed straight to the junk" I'd just remove the IP head and then remove the bolt. My guess since you were tightening the bolt it will be fairly easy to remove. Other than time, what do you have to lose?

But, removing the IP head has some risk as the little shim on the end of the Distributor Plunger Foot assembly is subject to fall out. Just prepare for it to fall out. Then, when going back together, use some grease or Vaseline to hold the shim in place (that's what I did).

Here are a few pics from my experience with the IP re-sealing. Sharing these for the sake of the readers. However, you may be far more familiar with these tasks and procedures that me.

Below, the little shim can be seen in the center of the pic (smallest object in the photo)



Below, in this pic you can see the Vaseline on the end of the foot. That's where the little shim goes.



Below, is where the Distributor Plunger Foot goes inside the IP with the Cam Plate installed first. Two rollers have been removed (fell out, easy to re-install).



Below, is a pic showing the IP head in a Vise. I had to literally scrape and brush the stuck O-ring out of the sealing groove.



Below, the head assembly is the bottom part of the pic.



As for it holding (not leaking), my guess is that it will not leak. The seal, as you know, is the O-ring. I think the other three bolts will keep everything tight and in place. You can always move forward with completing the job and then start the engine to see if it leaks.

Later today, I'll be re-sealing an IP with slightly over 401k miles on it!:eek: It had leaked/dripped on the ALT causing it to go out... Battery light ON is why the car was brought to me. Then, I discovered the leaky IP (she did say she had been smelling diesel fuel for a long time).

All of the pics can be seen here: http://pics.tdiclub.com/showgallery.php?cat=5690
 
Last edited:

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
I checked my old pump and the bolts are 6mm 10.9. Eyeballing the root diameter of the thread I got about .16", probably more. I found the minimum yield for 10.9 bolts is 136000 psi.

So, my backada napkin figgering gives the yield of one of the bolts as 2700 lb.

As I recall the high pressure plunger is about 1/2". Conservatively using 10000 psi as the injection pressure I get about 2000 lb as the axial load applied to the pump head.

So one bolt is strong enough to take the load but of course the loading would be off the axis of the bolt. The two bolts opposite each other solve that and give better than a 2:1 safety factor.

If it leaks it won't be due to the missing bolt since the seal is an o-ring as mentioned above and doesn't depend on the bolts being tight.

Did the head of the bolt touch before it broke? If no I don't have much hope of the piece coming out easily without removing the head. If it broke off before the head bottomed out then something was causing it to bind.

If it went all the way in by hand until the head had bottomed so the bolt was actually stretching when it let go the remains would probably be loose.

Might even be able to use a small chisel, tap on it to make a slight slot and turn it out.
 

jesiah

Member
Joined
Mar 7, 2018
Location
Portland
TDI
'03 Jetta Wagon
Thank you all very much for the input and help.

I'm finishing putting the fuel lines on and will hope it's all tight.
The bolt bottomed/was touching the IP head when it broke (the pic with it sticking out is just to show which one it is).

Fingers crossed...
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
next time, use the term, finger tight, LITERALLY.
looks like its just more work to fix it, good luck! seems like a pesky fix but at least its not locked up in there.
those bolts go back on with something like 96inchlbs, not sure exactly but its probably less i would think.
 

p377y7h33f

Veteran Member
Joined
Jun 24, 2011
Location
Brooklyn
TDI
2003 Jetta Wagon 5-Speed in Tornado Red
wild guess here, but the screw probably bottomed out because the small QA bracket wasn't under it. if that's why it broke, it might very well still be holding the head. why not try to back the head out again and see if it holds? the bracket can still be attached by the 5mm allen screw on the lower hole.
 

jesiah

Member
Joined
Mar 7, 2018
Location
Portland
TDI
'03 Jetta Wagon
Welp, 1,100 miles later (LA to Portland) and it appears to be holding fine with no leaks.

Fingers crossed it keeps holding.

Really appreciate everyone's input!
 

vincej

Veteran Member
Joined
Jun 26, 2015
Location
Calgary
TDI
2014 Golf Wagon
If there is enough room to somehow be able turn a drill bit you could get it out with an easy out. I'd make a sleeve first so the bit doesn't wander off. An angle drill might be the tool to get at it for access.

For sure the bolt is broke and not a case of stripped threads?
 

runonbeer

Maintenance EnthusiastVendor
Joined
Apr 15, 2002
Location
Austin, TX/Chapel Hill, NC
TDI
'00 Golf 02M, '10 Golf 02E, '02 UTE 02M
What a great post this is:)

I checked my old pump and the bolts are 6mm 10.9. Eyeballing the root diameter of the thread I got about .16", probably more. I found the minimum yield for 10.9 bolts is 136000 psi.

So, my backada napkin figgering gives the yield of one of the bolts as 2700 lb.

As I recall the high pressure plunger is about 1/2". Conservatively using 10000 psi as the injection pressure I get about 2000 lb as the axial load applied to the pump head.

So one bolt is strong enough to take the load but of course the loading would be off the axis of the bolt. The two bolts opposite each other solve that and give better than a 2:1 safety factor.

If it leaks it won't be due to the missing bolt since the seal is an o-ring as mentioned above and doesn't depend on the bolts being tight.

Did the head of the bolt touch before it broke? If no I don't have much hope of the piece coming out easily without removing the head. If it broke off before the head bottomed out then something was causing it to bind.

If it went all the way in by hand until the head had bottomed so the bolt was actually stretching when it let go the remains would probably be loose.

Might even be able to use a small chisel, tap on it to make a slight slot and turn it out.
 
Top