Thursday, July 28, 2016

Nurse... Scalpel. I mean, Dremel!

While we visit here in Pennsylvania, Nicole is taking advantage of the fact that she can take things apart.  Notice, we didn't say... and put them back together again. 

Whenever something goes wrong on the van, Nicole's mind wants to know... WHY?

So, despite our limited space, the one thing that there is always room for is old parts from the van.  If she has to get rid of clothes to be able to carry that old water pump until she can dissect it then so be it.  Priorities in order?  Check!

First up was the mechanical fuel pump. 

                   The original pump installed in 1988.  It lasted 28 years!

                                        This is it... a Carter original.

We're just going to say that this baby was not meant to be taken apart.  But, with the right tools and enough free time and 'desire', the task can certainly be achieved!

     It all started with sheer willpower and a few simple tools.  Pry open the roll crimp...

                                    and the pump will start talking to you!

We've heard varying reports that the intake gasket is supposed to be one way so that fuel does not drain back to the tank each time you turn the van off.  Both in and out looked pretty darn good though.  So, before taking them apart, Nicole filed the lid with water and watched.

Since water was coming out of both holes, it could then be assumed that fuel was draining back to the tank at shutoff which resulted in long cranks (to pump fuel back up to the front of the van) at each start-up.  Interesting but not the cause of the noise in the pump and even with this failure you can still drive so long as the pump is actually pumping and you're willing to crank a bit more now and then.

On to the rest of the pump...

That is a pretty darn good looking diaphragm considering the age.  Now it's time to break out the big guns and grind away at that rivet in the center and get into the meat of it.

Not too shabby.  Pretty sure that big spring there is the major contributor to our noise.
Still, things are in better condition than we expected considering the noise we were hearing.

The under-side of the diaphragm shows some age though the pump was still 'pump-able'.

This little gasket would keep fuel from sneaking out of the pump, past the pump arm and into the timing chain area.  Not sure it was doing a great job. 

Though, still not the cause of our noise, the wear on this part is understandable as it 'buffers' the up and down of the pump arm.

Forgot to take a 'before' photo but this is the pump arm almost free.  See that little piece of metal left from the pin.  The full size of the pin can be seen in the slot just above that.

Well, that's it.  Disassembly complete!  The diagnosis?  With nothing obvious presented, we were left with an assumption.  The only way to repeat the noise we had been hearing was to compress the larger spring to a point where the pump arm rode just a tiny bit loose.  So, it appears that the larger spring may have been the culprit in that it had grown very stiff and perhaps was binding a tad. 

Either way the noise immediately went away upon installation of the new pump.

Next to go under the scalpel (ahem, the dremel)...  Our battery isolator solenoid that we use to charge our house batteries from the alternator on gray days.

                                      What will this dissection reveal?