Fuel Pump - broken screws

[jedwards]

Gentlemen,
I am embarking on a rebuild of my early (tall ) fuel pump as I, like many others, had fuel dripping from the drain tube. 
Exactly as the Technical Manual predicated, three of the lower plate bold/screws and one of the inlet plate screws broke off just below the head, leaving about 3 mm of shaft protruding for the body.
I have read the advice in the manual, have thoroughly flushed the pump of fuel and plan to use heat and vice grips to carefully remove the remaining thread.

However, before I jump in and ruin what little metal is still protruding,  can anyone share how they succeeded with this task?  Applying heat and grapping 3mm of thread with clumsy vice grips might sound easy, but as in all things, there are always tricks of the trade that separate success from failure and failure in this case will destroy the rather valuable original pump.

Help please!

[tel76]

When I have done this task the remaining screw stub has always broken off flush with the mating surface, I ended up drilling out the old screw and installing Helicoils, a very time consuming job.
Start the drilling process with very fine centre pop and then a very small drill, it is very easy to slip off and go into the soft metal.

[George Des]

If only one broke off consider yourself lucky since the task will be much easier. The way I do this and it has been often is to take a disposable box cutter blade and wedge it between the body of the pump and the side plate oon the area of the plate where you were ableto remove the screws. Once you are able to get one blade in try to wedge another at another point on the plate. By going around the periphery of te plate with severl blades you will eventually lever the pl te up and over the remaining stud. You may even have to stack a few blades side by side to do this using a small hammer to gently push the blade in. Beware this is very dangerous as be sure to wear eye protection. Once the plate is removed you will have better access to the stud. Now apply heat to the stud. I use a small propane/oxy torch to get the stud cheery red then quench it with WD-1. Using the vice grip after this will allow you to remove the stud. I've done this countless times. It works even when most of the studs on the bottom plate have been broken fairly short. Drilling out and using helicoils should be your last option. It is very easy for the drill to slip ans bite into the surrounding aluminum and ruining it beyond repair. Again, be careful using the method I describe.

[Bonnyboy]

Yes, what George said but instead of using Wd-1 to quench the hot stud all the time I alternate with the aerosol freezing in a can on the stud and then the WD-40.  So far I have been lucky with no heli-coils necessary.  Lots of patience.   I also found that by using a teeny vice grip I can monitor the force that I am applying and hopefully avoid breaking off the stud. 

If I am going to drill the stud I finish off the top so I have a good start for the center punch and pilot drill.   I start with a finger drill (push down and it turns) to get a hole before going to the drill press.   Use real good drill bits and using a backwards drill with a hand held drill sometimes works as well as the whole stud may loosen out but only after I have made a better hole using the drill press. 

[George Des]

Yes I meant WD-40. WD-1 was the wire we used in the military!

[garymand]

Funny how those old things pop out from time to time.

[George Des]

Yeah, good old WD-1 and 100 mile an hour tape-the staples of field expediency. Wildly off topic but sometimes wonder if this generation of military members still use these kinds of things