Hydraulic Test Bench - Fenwick 3654-T

This was something of an early birthday present - albeit a broken birthday present....

(Credit: George Antoniou)

The Fenwick 3654-T is the LHM version of a manually operated (hand-pumped) test bench for carrying out many pressure tests on DS components.

With the right connections, it can be used to test and/ or set:

• sphere pressures,
• pressure regulator cut in and cut out
• steering rack cross-over pressure
• Brake (valve) switch pressure

And many others besides.

A friend - George - advertised it for sale on Facebook back in June.

Too good to miss.....

But there was a problem.George had had the pressure gauges serviced and calibrated way back in 2016, but the pump itself, didn't work. When pumped, it didn't hold pressure. He'd had a Citroen hydraulics specialist look at it but they'd been unable to get to the source of the problem. George was now passing the bench on to someone else to try. I went in 'eyes-open' and decided to take a punt. If I can fix it, I'm sure it will come in handy. At the very least it's a beautiful piece of DS history and, if I can't get it going, I am sure there will be someone else along who was willing to have a go.

I popped up to see George yesterday and collected the bench. It's  showing its age, but it's still in its original green paint. Interestingly, not the same colour you find on LHM parts on a DS - but original nonetheless.

It looks lovely to me. Especially with a thick patina of old LHM and still has the original brass filler cap and wooden handled lever. 

It has three pressure gauges - two that read upto 200bar, and a big one that reads to 100bar. They look to be the original 'Bourdon' gauges for this board.

100 bar pressure gauge

All three gauges still have the connectors that will allow me to connect hydraulic pipes as necessary.

Someone has also made some wooden covers to protect the glass of the dials when the bench isn't in use. 

Homemade covers over dials

Those covers look every bit as old as the bench and - as basic as they are - I love them as they are part of this bench's history.

The bench has a few electrical connections and a bulb - looking suspiciously like a DS boot light. That can be used to test the hydraulic pressure at which the brake/ pressure warning light activates, for example.

Electrical test lamp

It also includes one of the main pieces of kit - the screw cap to fit to spheres for pressure testing. 

Fitting for sphere testing

Though there are telltale signs of Araldite on the pipe so maybe this leaks?

Signs of repair

What it lacks all the pipe accessories to join it to things such as the steering rack. 

Accessory board for the LHS version of the bench

These, and their storage board were sold separately as part 3655-T. However I've got some fairly good photos of what those pipes would have been like and hope that, over time, I can get those made up - or make them myself using old pipe fittings.

I've found some online copies of some of the operating/ testing instructions. Though they are incomplete. And in French of course......

Operating and test instructions (credit: 'BK23' site)

First things first though, and I need to get it working. Before this LHM version, there was an LHS version of the bench - Fenwick part 2290-T and after a lot of searching and rabbit holes I've found some very helpful strip down and rebuild instructions for an LHS version. Hopefully they can guide me as I try to repair this LHM version.

Step by step instructions (credit: 'HD19' site)

Dismantled (credit: 'HD19' site)

A restored LHS version of the pump (credit: 'HD19' site)

I've seen pictures of one of these restored and for sale on Ebay, but it was missing a few pieces. 

Testing sphere pressure

Nothing that couldn't be replaced though if you wanted the full set-up. Alternatively, you can buy a reproduction of this bench. 

Modern equivalent (credit: Dirk Sassen)

But they're not cheap!

Perhaps you can see now why I was so willing to take a punt on this broken bench. 

But you don't need to splash out. You can make a basic pressure tester from a bottle jack.......

(Credit: Xantos on Frenchcarforum)

(Credit: Classicjalopy)

(Credit: Citroenvie)

(Credit: Citroenvie)

A helpful guide for making one of these can be found HERE.

And you can make one from an HP pump.

Hand-cranked HP pump

Other people have gone the other way and built some very elaborate rigs that put my one to shame.........

(Credit: Loris Carrer)

And Citrothello will even walk you through the steps to build one.

Comprehensive rig (credit: Citrothello)

Tempted? You find out more HERE.

But the folk have bigger set-ups and probably need such rigs for their businesses. And of course, you can overdo it......

Checking steering rack cross-over pressure. No - really......

I don't need all of that. Providing I can get it going, this little rig will be ideal for my more modest (and hopefully only occasional) needs.