4wd Relay Clicking At Idle

[messanic]

I see exactly the same thing; I think the power drops are just because it draws so much current (the attesa pump that it's switching on/off seems to cause a voltage drop as it's turned on). Lights flash dim for a very brief second; have to be watching to notice.

from my understanding its not the pump that turns on and off its basically the system checking it has enuf pressure in the system.,..... it needs to keep a constant pressure so if the attesa does need to engage it can straight away mine drew alot of power when it clicked... lights would dim my subs would cut out.... not good.... mine will click every 5-10 mins now which is acceptable... well apparently

[DaveB]

Pity about the licence... thanks for the reply though, better late than never

[wolverine]

does this mean the accumulator is damaged beyond repair or is there a potential electrical issue to/from the accumulator?

[KiwiRS4T]

I have all the Attessa stuff that sits on top of the diff as well as the Atessa computer from my S1 which did not make any clicking noises that I could notice and can supply at not retail, not trade, and even better than staff prices ... in other words mates rates (much less than $1600) so contact me if you need something!

BTW dropping the diff is not the major that it sounds. You can unbolt the subframe and lower it quite a bit while leaving everything connected (probably have to take the exhaust off its hangers too). Just jack the car up, put axle stands under the chassis and then undo the four subframe bolts (or nuts I forget which) and lower the diff down on the jack.

[wolverine]

cheers,

the attessa seems to work fine it is just the clicking. next time a sparky gets near it they can spend a few mins poking around.

[DaveB]

Also I think the hard part about changing it is reconnecting the hydraulic line from the transfer case. I think it would need new seals, and it needs to be bled.

[EGA41T]

cheers,

the attessa seems to work fine it is just the clicking. next time a sparky gets near it they can spend a few mins poking around.

Lol you still chasing this clicking?

its got to be a couple of years since you were telling me about it.

[BCCairns]

Hey Wolverine - You still living with this clicking?

Picked up a Stagea last week and im having the same clicking from my Relay. If I disconnect the relay I get the 4WD light come on but when it is connected it clicks every 5 to 10 seconds but no warning lights and it seems 100% fine.

Just interested if you have lived with it for a year without a problem, seems from reading GTR forums they have a similar sensor in the boot and it seems commen and people live with it.

Tempted to just live with it.

Interested to hear thoughts.

Cheers,

[wolverine]

It still clicks, it still annoys me, it doesn't seem to have any negative effect.

[BCCairns]

It still clicks, it still annoys me, it doesn't seem to have any negative effect.

Cheers heaps man, well looks like my 1999 RS4 S is joining the stagea clicking crew.

[DaveB]

Well I think mine is clicking more now than it used to (unless it's just the hot weather or something) and it is starting to annoy the (*#&% out of me... if anyone has a second-hand known good attesa/accumulator unit (from above the rear diff') please let me know... if I can find one I will get the mechanic to install it.

[KiwiRS4T]

Well I think mine is clicking more now than it used to (unless it's just the hot weather or something) and it is starting to annoy the (*#&% out of me... if anyone has a second-hand known good attesa/accumulator unit (from above the rear diff') please let me know... if I can find one I will get the mechanic to install it.

Have sent you PM re my S1 unit - let me know if you don't get it.

[DaveB]

Thanks Bob PM replied - I just didn't get the attachments

[DaveB]

Got them now, thanks for that. If I can get this sorted, I will post a "how to" for people who are being driven mad by the infernal clicking like me

[BCCairns]

Got them now, thanks for that. If I can get this sorted, I will post a "how to" for people who are being driven mad by the infernal clicking like me

If you can get that sorted, u deserve champ status.

[DaveB]

If you can get that sorted, u deserve champ status.

Well Bob (KiwiRS4T) has already helped out with detailed photos, part numbers and removal details so I think it is possible. I should soon know

[BCCairns]

Well Bob (KiwiRS4T) has already helped out with detailed photos, part numbers and removal details so I think it is possible. I should soon know

Ahh sweet, Nice work guys!

[DaveB]

Ok well, I've done some investigation and found another post on SAU about this relay problem with GTRs and added some pics and details to that - check it out here:

http://www.skylinesaustralia.com/forums/R3...18#entry5041918

Then a PM from another guy who has seen a similar issue with Aristos (they apparently have an electro-hydraulic brake setup which is susceptible to the same problem) just seemed to make a lot of sense.

I think I know what our problem is (and this was probably painfully obvious to anybody who knows anything about hydraulic systems)!

The accumulator unit is actually a cylinder of high-pressure nitrogen, and the hydraulic pressure is stored against it, it is like a constant weight that keeps pressure in the hydraulic system. (I am wondering if the '32 system doesn't have one of these - this might be the "pre-load" that people talk about on '33 and '34... but I digress)

Anywho, just like a dodgy gas lift chair, the damn pressure vessel leaks out over time and goes flat. As this happens, less and less hydraulic pressure can be stored, and the pump has to be switched on at shorter and shorter intervals, thus the relay clicks more and more... it all sounds plausible to me...

So apparently it's as simple as removing the cylinder and taking it to a gas strut recharger to get recharged! Might cost all of ~$150 ?

At any rate, I'm now thinking it's not the pressure switch itself. And it's definitely not the pump. So the accumulator is the only thing left.

Beware if removing it - I know nothing about the correct procedure and the instructions on the canister warn against disassembly; I'm unsure whether removing it will vent the high-pressure gas or not. But I have been told by one forum member who says he has done it, that the procedure is to release the hydraulic pressure (with ignition OFF) by opening (CAREFULLY) the bleed nipple(s) on the attesa unit under the car to release the hydraulic pressure, and then once that's gone, to remove the gas canister and take it to be recharged.

Sounds all too good to be true. But I probably won't be able to say for sure myself whether this method will work because I'm probably just going to swap the whole damn lot for a known working unit which I got for a good price second-hand

here's hoping someone will try it and we'll solve this mystery once-and-for-all...

DaveB

Edited January 19, 2010 by DaveB

[DaveB]

I decided to try to remove the accumulator anyway, since whatever I do on the car I'm going to have to remove it. Turns out it just unscrews like I was told. Had to use a G-clamp to get it off but I didn't need huge force or anything. Just make sure to remove the hydraulic pressure first via the bleeder (with ignition OFF) and you should be right.

So here's what an accumulator looks like:

that's the little SOB that causes the ATTESA relay to make all the noise. So annoying it is... not for much longer. The plan is that I'll just unscrew the accumulator on the car, and screw this new unit (well 2nd hand) on in place; it has a known working history so it should hopefully be charged up OK.

I'll probably see if I can get the garage to do it while it's on the hoist, as it's a bit of a pain to get to mine with my 3" exhaust hanging just under the diff'.

Edited January 20, 2010 by DaveB

[wolverine]