Sunday, March 11, 2018

CAV Fuel Filter Housing Revisited


This is the bane of my existence. This is a 90 degree connector and I needed just one straight adapter. One end is 5/16 (1/2x20 thread) SAE 45-degree flare, the other end is O-ring boss with 1/2 x 20 thread. Not NPT. Not 37-degree flare. Not inverted flare. If I found a website with O-ring boss male adapters they either did not have the correct sized ends or the flare was 37-degree.
Figure B
Was it easy to acquire?
Sure. As easy as putting a half pound of butter in a tigers ear in a dark basement with a hot needle(Sir P.G. Wodehouse).
Yes, it was that easy. In fact I never sourced one.

In October of 1999, I replaced the original CAV fuel filter housing with an AC T-95 spin on filter housing. It was supposed to make changing the filter easier and priming the fuel system easier as well by allowing the filling of the filter with fuel prior to installation.

The filter housing had 2 In and 2 Out ports, one output I used as a bleed port. I have no idea where I got the fittings, but all hoses connected to the filter housing via four 90 degree connectors shown above, see Figure B, B for Bane.

For some reason after changing the Glow Plugs in November, the fuel system developed an air leak and when trying to bleed through the top port of the filter, things only got worse. That port would not stop leaking.
 So out with the new
 and in with the old.

I returned to the original CAV Filter housing. I used a Union Nut (RN (Rovers North) PLQ637) and olive (RN 530966) to connect a 1/4" hard line to the Filter port. The other side of the hard line eventually terminated in a SAE male flare.
I used a funnel to fill the filter via the top port (where the banjo is) prior to purging the fuel lines of air. Saves on many manual pumps of the fuel pump.
 This is the Banjo Bolt (RN part 563195) on the #4 Injector Nozzle Spill Rail. The previous bolt was rounded and I had problems separating the hose adapter from the banjo bolt. I also ordered a spare banjo bolt for the other injectors (RN273521) in case I wanted to omit the hose from the filter to #4 injector. I had read that on later/earlier 2.25 diesels this was not used, but could not find a second verifiable source, so I kept it. I had already made a new hose for this connection. The new banjo bolt washers were (RN 273069)

 After plumbing all the lines, after filling the filter with diesel, after starting to purge the system of air, I noticed the hose to the injector pump was leaking at the injector end. So I decided to replace more hoses. Of course the fittings were different for both hoses on the Injector pump.

Hoses:
   Filter to #4 Injector      = 3/16" hose   banjo to flare  1 foot in length
   Filter to Injector Pump = 1/4" hose     flare to flare    1.5 foot in length
   Injector Pump to Filter = 5/16" hose   flare to flare    2 foot in length

After replacing the hoses and another round of purging, starting the engine was to be next, but was not to be. The battery decided not to cooperate.
Charged the battery while lunch was consumed and about an hour later the engine started right up.  I let it idle for more than the legal limit and then stopped it and restarted it. Hope it starts tomorrow. A new battery will be a project for next weekend.


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