Continuous Ticking - PR Return line blown off

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roscoe
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Continuous Ticking - PR Return line blown off

Post by roscoe » Fri Mar 24, 2006 9:15 am

Hi All
I have a little emergency with my TZD- the clear return line from the PR blew off today while SWMBO was driving it - so tonight I took some tools and LHM over to where she left the car and stuck the line back on - held on with a hose clamp. Filled up the reservoir and drove it home with a constant ticking from the PR - like every second. The line held but it looks like a pretty heavy flow of LHM through it - so am I right in thinking my PR has failed? I have a spare one on my parts car to replace it with, but wanted a second opinion before pulling it off...mainly because the TZD lines are nice and rusty (ex UK car) while the parts car is not...nice Australian car!
Also have a nice oily near side front wheel, brake and hub to clean up now too...so will swap the brake pads over from the parts car as I'm pretty sure the TZD ones are soaked in LHM.
cheers,
Roscoe
1991 TZD
2004 Peugeot 307
1990 Mitsubishi Express Van - Alpaca Transporter

AlanS
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Post by AlanS » Fri Mar 24, 2006 9:32 am

Not just a totally stuffed accumulator sphere by any chance?
Trying to imagine what would "go" inside a P/R so suddenly to cause such a catastrophic failure.
I can understand the membrane in the accumulator just rupturing though.


Alan S
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roscoe
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Post by roscoe » Fri Mar 24, 2006 9:44 am

The sphere is a possibility - I regassed it in November at our club tech day and it wasn't that far down at the time - so will swap it with the parts car one - although I know that acc sphere only has about 20 bar in it. This car has always had a fast ticking PR - even with a fully charged acc sphere I never got it below 10-15 seconds. I've rebuilt the doseur valve, and have pulled the return lines off the reservoir to see which of them is flowing heavily - none of them appeared to be - although I couldn't get the third one off (the one with the check ball in it).
cheers,
Roscoe
1991 TZD
2004 Peugeot 307
1990 Mitsubishi Express Van - Alpaca Transporter

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Post by AlanS » Fri Mar 24, 2006 10:04 am

I've never been able to get my head around the flow diverter principles, but as the accumulator ticks like crazy whenever you turn the wheel, is it possible that it may be a culprit also?

If Anders or someone can come up with the URL for the return lines diagram as was posted on that old Japanese site, that might give you some clues by identifying which line is spewing LHM.


Alan S
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Post by jeremy » Fri Mar 24, 2006 10:06 am

Regulators in fact seldom give terminal problems but the tick speed is influenced by 2 factors - the accumulator sphere and the non-return valve.

The accumulator can be tested easily by setting the car to normal height and running the engine for a couple of minutes. Turn off the engine and sit in the boot. the car should sink a long way (back suspension is moving as it should) then after about 30 seconds rise to its original height. (height corrector has opened and the accumulator is raising the car), When you get out it wil rise again (back spheres are OK) and then fall again after about 30 seconds (height corrector's doing its stuff)

The other cause is the failure of the non-return valve seat. This can be repaired quite simply - remove the sphere and on its face on the regulator you will find a strange shaped metal plate secured by a bolt. remove the bolt and the plate and a ball bearing will fall out. Catch it, put it back in the hole with a dab of grease and then tap it ONCE smartly with a brass punch (and hammer of course). re-assemble.

You must use a brass punch - steel will put a flat on the ball. (First one I did I used an old copper mig nozzle held on to a steel punch with a sleeve which was in fact an old LHM seal!). You must only hit it once - not try and rivet it in place. The ideal is to make a nice seat for the ball to seal on and multiple blows will make multiple overlapping seats rather than one good one!

The other thing to check is that the pressure relief ball bearing (under the P-R bolt) is still there - it should be unless someone has lost it by undoing the bolt completely. This is NOT the same size ball as the non-return valve. (Size is shown in the parts book - I have a downloaded one if you need to know the size.)

I have done the re-seating job on my TD BX with the regulator in situ - working from underneath. It doesn't take long and I certainly can't remove the regulator in about 5 times as long as that job takes!

jeremy

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Post by roscoe » Fri Mar 24, 2006 10:12 am

I've done the ball reseating job on this car - didn't make a lot of difference to the tick speed, same as a fresh acc. sphere. The ball under the pressure release screw is there - I checked that when I regassed the sphere. So tomorrow I'll do the 'sit in the boot' test and see if it is the sphere - but I'm still puzzled why the return line blew off and the LHM coming out of the PR was under pressure - it shouldn't have been?
cheers,
Roscoe
1991 TZD
2004 Peugeot 307
1990 Mitsubishi Express Van - Alpaca Transporter

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Post by jeremy » Fri Mar 24, 2006 10:24 am

There are 3 ways high pressure LHM can escape from the accumulator - one is onward to the safety valve - the way it should go, one is back the way it came via the non-return valve and the third is down the shaft of the piston in the middle of the regulator which is unusual - but if this has worn you will have to change the regulator. It would then probably overload the circuits in side the regulator and be discharged via the return pipe.

However if the accumulator is flat it is not providing any cushion for pulses of pressure received from the pump and so a regulator that would seal adequately with a good sphere may leak the higher pressure pulses with a flat one.

From the problems people have with re-gasses spheres I am forced to ask the question - 'Why bother?' As a precaution I replaced the accumulator on my BX last year when it was about 3.5 years old (and I wasn't sure of its origins) and the new one seemed to be exactly the same in performance. I was concerned as its health is essential for the proper functioning of the ABS.

jeremy

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Post by Stewart (oily!) » Fri Mar 24, 2006 10:25 am

That happened to me a couple of years ago, it hosed the nearside brake with LHM too, I ended up replacing the regulator and FDV with parts from my scrapper, and I got a refund on a very recently fitted Acc sphere
I dont know which bit was the cuplrit but its gone now, I think the sphere diaphragm ruptured causing the line to blow off, my LHM was milky looking at the time too, probably the gas in it.
Stewart
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Post by sleepy0905 » Fri Mar 24, 2006 10:34 am

This has happened to me as well i replaced the pressure regulator and flow distributor and cured it.
The garage we got the car from replaced the steering rack/ safety valve/steering ram and pinion valve with no luck so as a temporary (2 years) repair they put a T piece in the clear pipe just as it comes out of the PR then put a length of pipe from the T piece back to the resevoir cap and remove the vent pipe from the cap and connect it in there you now have a direct line straight to the resevoir. this lasted me till i replaced the PR and FD this was a common fix on the BX taxis that was running round lincoln.
That is a R Barnard Garage well known fix in Lincoln
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Post by roscoe » Fri Mar 24, 2006 10:53 am

I think I'll go ahead and replace the PR and FDV on the car as the parts one is easy to get off now (rad is out) and the TZD has lots of room down there - and it might fix the ongoing fast ticking problem I've always had with that car. Will also use the (likely flat) Acc sphere off the parts car until I can either get it checked/regassed or get a new one (Jeremy - the reason we regas down here is $15 vs $100 for a sphere).
I've got some new pipe seals so with lots of WD40 on the joints, should be able to get them off...
The hydraulics on the parts car were good - when I had it running the ticking was 30+ seconds and that was with a low Acc sphere.
cheers,
Roscoe
1991 TZD
2004 Peugeot 307
1990 Mitsubishi Express Van - Alpaca Transporter

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Post by mnde » Fri Mar 24, 2006 10:48 pm

If the accumulator sprayed LHM a long long way, then is it likely that the diaphragm was ruptured? I recently changed front spheres on a Mk1 BX that were absolutely knackered. One of them erupted a stream of LHM - spewing into my friend's eye, all over my face, the engine bay, and then *several feet* into the garden next door when I'd swung it round. The car has remained stationary all week without being started, so there was no pressure

I was told it was the remaining pressurised nitrogen streaming through the diaphragm and ejecting the LHM t'other side through the hole.

I guess even a two month old accumulator could theoretically suffer a diaphragm failure because of a weakness in the diaphragm material. Was it two months old from when you bought it, or from the date stamped on it? 70 bar is an awful lot of pressure to push LHM through the hole in the bottom with! :shock:

Mark.
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roscoe
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Post by roscoe » Tue Mar 28, 2006 12:15 am

Yep, I've had my problems with both the TZD and 16V this year - the cars must be like me and starting to show their age :( Anyway, pulled the PR and FD off the parts car Sunday, but before replacing my TZD ones, I replace the accumulator sphere with the parts car one and the ticking slowed down to about 10 seconds, so those that said it was a blown sphere - BINGO!. I've ordered a new accumulator sphere ($150 GULP) and will try it for a few days. If the ticking doesn't get up close to the 45-60 second mark, I'm going to then swap out the PR and FD as well. I know the ones off the parts car were good as even with the low accumulator sphere on it (40 bar tested), it was ticking at around the 60 second mark.
So more fun and games to come....at least the 16V is sorted and running like a dream...and now up for sale :shock:
cheers,
Roscoe
1991 TZD
2004 Peugeot 307
1990 Mitsubishi Express Van - Alpaca Transporter

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Post by AlanS » Tue Mar 28, 2006 2:22 am

Which one of Ned Kellys direct descendants quoted A$150 for an accumulator sphere?:shock: :shock:

I understand that Elliot from the French Garage in Morrabbin is supposedly getting spheres now that are comparable to overseas prices, although teh first time someone tried to buy a couple he found a good excuse to hike them up 20 bux or so, but still better by comparison to most others.
Martin Bray in South Australia I think does the accumulator for around $100 also.

Alan S
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roscoe
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Post by roscoe » Wed Mar 29, 2006 4:26 am

One well know Sydney Citroen dealer - usually very good on prices and service, and my local Citreon dealer - both within a couple of $ of each other... Haven't tried Yongy yet or Martin Bray but will now - thanks.
cheers,
Roscoe
1991 TZD
2004 Peugeot 307
1990 Mitsubishi Express Van - Alpaca Transporter