Hydraulic Bench Tester

A must if you are working on your D. The most expensive part here is the pressure gauge; it goes to 3000 PSI. I made it removable since it is part of a cross over gauge for a steering rack.

The output can be either 4.5mm (3/16”) or 6.35mm (¼”) in order to test any component on a DS or ID. The line with a loop is to test a HP pump and the straight one is plugged to test the integrity of the tester.

I have started with a cheap (less than $10) 2 ton hydraulic jack.	Then I gathered a plug fro the top of the cylinder, some American and Citroen fittings, A pressure gauge and a fuel filter.
First, I remove the little rubber plug and soldered a 1/4” line with a square angle.	I have cut the fuel filter in half, remove the filtering element and grinded the piece on line inside, to make a funnel for feeding the pump with hydraulic fluid.
To make it pretty and differentiate it from a brake fluid tester, I painted it LHM green.	The plug is welded on the top and I drilled a 3/16” hole. Turned out later that the weld was not airtight. I silver brazed it later to fix it.
I made a flare inside to make sure that the line cannot come out under pressure. I used a straight output to be able to put the pump apart for repair and make sure I don’t have an issue with alignment later. All the lines are silver brazed.	I have also silver brazed the top of the plug and the cylinder together to make it hermetic. Here the cylinder is upside down. I have also used the o ring that was on the piston at the bottom of the cylinder to avoid leaks at high pressure.
Time to braze all the lines.	The tester is finally done. I had a lot of issues with internal leaks but all the bugs are ironed out.
I stopped at 2100 PSI. I got a little nervous. The system holds the pressure nicely.	The first pump to be tested. I could not go over 1200 PSI due to a leak at the cover; I suspect a cracked body. Somehow, the pump held the pressure though… Can’t wait to put this pump apart…