Pressure regulator has lost its tick

[awatt_bx19rd]

Just changed the engine in my 19RD from an XUD9 to an XUD9TE. Managed to sort most of the problems fairly straightforwardly, except for this one:

Now that I've got the replacement engine fired up, the pressure regulator is simply not cutting out!

Okay, so it might be helpful to list some observations that I have made:

-There's no tick time whatsoever
-The pump pumps continuously with no relief from the PRV so it's obviously not reaching "cut out" state.
-The main return hose and LHM reservoir both get extremely hot after about 20 minutes of just idling in the driveway.
-Suspension and brakes seem to have plenty of pressure to do their jobs. AOK!
-Power steering assistance almost non-existent on the test drive.

The hydraulic stuff I've fiddled with since the last time when it was all working properly:

--Return hoses: all been changed (except brake valve ones)
--LHM pump: fitted one from a Xantia (still running the original FDV and everything else hydraulic that was formerly on this car)
--Have done my best to bleed the system of air - done Citrobics, brakes bled, regulator relief screw undone (with an unusually loud whistle, by the way) test driven, and repeated Citrobics.

So after many Citrobics sessions there's still no tick time and the power steering is still non-existent.

I've probably made some real silly error here...What on earth could it be??

[mat_fenwick]

Welcome and congratulations on your fine choice of engine!

LHM pump: fitted one from a Xantia (still running the original FDV and everything else hydraulic that was formerly on this car)

Was this from a very early Xantia that still had the BX set up? Or the usual Xantia type without an FDV?

[citronut]

what he said / \

regards malcolm

[awatt_bx19rd]

Thanks for the welcome Mat. My one looks nearly the same as yours, although minus the alloys, plus four years of age, and slightly different trim strips.

Don't think the Xantia had an FDV on it. I believe they call this one a "6+2" pump? What I did to this pump when I got it was remove both suspension pistons, remove half the steering pistons, so it's now a 3-piston pump.

Admittedly this was all slightly experimental for me, and while I haven't done an actual volume test to measure the cc output per revolution, just going by the eye-o-meter, it appeared to be spitting at least as much green blood as the BX pump used to.

Would you recommend that I pull the pump to actually measure and compare the volume per revolution of each pump, and if so, would that be a safe way of proving that this pump is up to snuff for use on a BX?

[Stinkwheel]

Im going to ask a stupid question,

Why not use a good or re-furbished BX pump and FDV etc - that way you know it will work as intended (hopefully)

Im not being awkwards, im sure you have good reason, even if it is just a case of 'i wanted to do it that way'

[citronut]

or why dont you use a XANT pump that was originally running with an FDV

regards malcolm

[MULLEY]

It will be interesting to know if that xantia pump does work correctly, might be easier to source for the future than a bx pump.

[awatt_bx19rd]

As it turned out, a regular Xantia pump was just much easier to come by.

The advantages as I see them.... dismantling-friendly, less cumbersome in the engine bay, no need to worry about slippage caused by a loose v-belt. The main reason for choosing it was that the shape of this camshaft is not right for mounting a pump-drive pulley on it because a vacuum pump was there previously.

Anyhow, I noticed somebody was already using one on their car and they recommended it to me, so that's why I decided to try it. I just hope I haven't done a bad job of it by cocking up something really obvious thing. I forgot to mention that the accumulator sphere is only 2-3 years old, so I don't suspect that's flat. I'll try measuring the volume of both pumps and report back.

[citronut]

if the accumulator sphere were flat the regulator would be ticking more frequently, not less,

maybe the XANT pump you saw fitted to the other car was from an early car that had the FDV fitted as the BX has,

also i thought the like of the XANT runs at around 2,600 psi and the BX at 2,500,
so maybe you need the regulator from the XANT as well

regards malcolm

[BX Bandit]

Well if it's a 6+2 pump that sits above the alternator then you don't need an fdv! But you'll need to feed the power steering control valve from (I think) the 2 side of the pump directly. So you'll either have to run a new pipe or make an adapter to fit between your new pump and the feed to the steering control valve (the one the fdv originally fed) the bloke to speak to us Vanny who did this temporarily with a Diesel engine in his valver whilst his valver engine was rebuilt.

However, unless you really know your hydraulics and are intimate with the workings of both bx and xantia 6+2 systems I'd be very careful. There is a priority safety valve that reserves pressure for your brakes in the event of hydraulic failure and whilst I believe it will still work as planned for your brakes, steering is number 2 priority. I believe this valve to be pressure rather than flow controlled but if you are removing pistons from your pump, and combining components that operate at different pressures then you're on thin ice and possibly you'll loose an insurance claim because of it.

Vanny swore by the conversion and I considered it myself but I stuck to standard set up as I've not had fdv woes.

Your other option would be to scource the correct camshaft, but you'll need to blank off the oil feed to the vac pump on the end of e head.

Apologies if that sounded a bit lecturous, but safety concerns should be number one!

[mat_fenwick]

You could put in the camshaft from your old NA engine, which is what I did. Apparently it has a very similar profile to that of the performance cam available for the engine (listed for a 306 so still won't be able to drive the BX pump), and mine certainly works well.

[citsncycles]

I was discussing pump options with Andy Weston, my local specialist when I was considering the 2.1 build for Timex. He had done similar conversions in the past on customers cars and said it worked well. the only difficult bit as far as he remembered was getting the pipe made up from the pump to the power steering, although between him and his Dad, they've worked on more of these cars than I ever will!

[awatt_bx19rd]

Interesting point about not needing an FDV. Sounds like custom piping would be involved though. Physically fitting and plumbing the Xantia pump with a single output requires no custom creation at all. All you need to do is slightly bend the metal pipe that came with the Xantia.

I spun a few LHM pumps over by hand and let the LHM spill into a container which I then measured the contents of.

BX: 4.9 cc's/engine revolution
Xantia 3-piston: somewhere in the ballpark of 4 cc's (didn't measure that one too accurately!)
Xantia 6-piston: 6.5 cc's

The 3-piston pump appears to be the probable cause for my problem, if these numbers are anything to go by..

Will the 6-piston pump supply enough pressure to make the regulator click? I'll slap it on there today and see what happens.

[awatt_bx19rd]

Fitted. Still no click. The only diffierence is that the pump makes more straining noises, the regulator whistles even louder when I open it, and I am guessing that the fluid which flows back through the regulator return is getting hot even quicker. Well, what a weird one. Ideas?

Perhaps I'll have to buy some sort of pressure gauge and create an adapter to plumb it in with. Anyone had experience with building one of those?

[BX Bandit]

Seems to be confusion here. If it is the type of pump that sits above the alternator (not below the cam shaft) and driven by the serpentine belt then you should two outlets from the pump. The 6+2 refers to the fact that there are are pump chambers, one with 6 pistons and one with 2 pistons. The 6 piston chamber feeds the braking and suspension and the 2 chamber feeds the steering. With a dedicated outlet for the steering, you don't need the fdv. And yes you'll need extra piping.

What I think you're trying to do is just substitute a xantia pump (serpentine belt driven style) to feed the rest of the standard bx system? Which in theory should be straight forward and I'm beginning (I think) to understand the nature of your problem.

Can you get a picture of your xantia pump?
If not, does it have one or two outlets?
Are you using both or just one?
Are you using a bx or xantia pressure reg?
Describe exactly what you have done, especially on the plumbing.

I'd not run it any more in case you start to do damage!