Replacement AYC Pressure Switch

As some of you who've been reading stuff on ClubVR4 (and some NZ members) will know, one of the most common problems with the AYC system in VR4's is the pressure switch. This problem is exacerbated by the AYC hydraulic pump losing pressure as it ages, causing the pressure switch to trip less and less frequently due to the high pressure required for the stock switch, which is further compounded in hot weather (such as we get all the time) as the fluids heat up and become more viscious.

In the UK, Malc supplies a replacement switch set to 9 bar (130psi) which relieves these problems (unless your pump is screwed completely), and he even did some legwork for us by finding a company in Australia who make a similar product here.

MPBVr4 said:

Hey Guys,

If it's your AYC switch playing up - RED light on when it's hot read on.
In the UK I supply a switch to replace the factory one, set @ 9 Bar (130 psig). This will extend the life of your pump as Kieran already stated. You will need a normally closed switch for all pre-facelift and normally open for post-facelift cars 2001 on. (There is a full write-up in members section CVR4)

Done a bit searching for you and this place should be able to supply a similar switch.

http://www.anzcontrols.com.au/ANZ Full Catalogue 07_files/page0009.htm

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I've just been in contact with ANZ Controls and obtained pricing on these for those who are interested.

The unit you want is as follows:

Pre-Facelift - Model 0167 Part Number 670 812 003 normally closed pressure switch set to 9 bar (130psi).
Facelift - Model 0167 Part Number 670 712 003 normally open pressure switch set to 9 bar (130psi).

**Please note: Early facelifts actually use the normally closed switch, as per Malc's post below. Only vehicles manufactured from 2001 on used the normally open switch. If you're unsure, take a look at the switch on your AYC pump - if it has a black top its normally closed, green top is normally open. MAKE SURE YOU USE THE CORRECT SWITCH!!**

These are AUD$93.50 each. You can also get the pressure set by them for $8.80 per unit. Shipping is via courier at $22 to all states and is usually next day delivery.

The optional rubber cap with dual cable duct (Part Number 662 100 003) is an extra $10.45.

Their contact page is here for those wanting to order one.

Pressure switch replacement guide here.

You're a legend SA! Much appreciated (I currently am seriously considering having my AYC bled and serviced because its making strange growling sounds)...

/Chris orders one immediately

Yep Chris if the AYC diff is making noise, it could just be as simple as air in the system, so a bleed will fix that. However considering you don't know how long it is since it was serviced, I strongly recommend doing a full service on it.

I'm planning on doing one on my car soon, including working out how to do a complete air bleed by running power directly to the AYC components without running the engine (replicating what happens when you connect an MUT-II). If I manage it without blowing anything up, details will be posted in a guide in a few weeks, so stay tuned

UPDATE: AYC servicing guide posted here.

So if I'm goiing to get by AYC serviced soon, wel just fluids changed would it be worth while ording these too if there is nothing wrong with my AYC?
Is it easy to install?

__ET__ said:

So if I'm goiing to get by AYC serviced soon, wel just fluids changed would it be worth while ording these too if there is nothing wrong with my AYC?
Is it easy to install?

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I assume you meant:

"So if I'm goiing to get my AYC serviced soon, when I get the fluids changed would it be worthwhile ording a pressure switch too, even if there is nothing wrong with my AYC?
Is it easy to install?"

If so, then the answers to your questions are Yes, its easy to replace (there's a guide in the Member's section of ClubVR4 on how to do it), but no, I don't recommend you go replacing it if you're not actually having any problems. Your AYC pump and switch may be perfectly ok for years yet - its easy enough to do if you ever need to, so just wait until your AYC lights start going red and then worry about it.

Unless you can't think of a better use for your $130, of course *shrugs*

Yes thanks for fixing my engrish.

Well I’m defiantly not going to buy one I’m already low on funds and mine work super, and wow the AYC bar can turn red, hope I never see them change to red, I always get 3 green bars well 0-3 depending...

MPBVr4 said:

You will need a normally closed switch for all pre-facelift and normally open for post-facelift cars 2001 on

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what about for the post-facelift cars built between 98 and 2001? which switch do they need?

Thanks a lot for this thread Trev, makes it very easy for us!

Simon I'm pretty sure all Series 2 use the same switch, I'm not sure why Malc specified 2001 on. You might want to send him a PM on CVR4 just to confirm though

And you're welcome, as always

SiliconAngel said:

Simon I'm pretty sure all Series 2 use the same switch, I'm not sure why Malc specified 2001 on. You might want to send him a PM on CVR4 just to confirm though

And you're welcome, as always

Click to expand...

There was a change over period we have found. Early facelift used normally closed switch from about 2001 they used a normally open switch.
To identify if you're not sure - have a look at your original switch.

Black top - Normally closed. Earlier VR4's
Green top - Normally open. Later VR4's

The change came about when the EVO6 Tommi Mak was brought out.

Part No used in the UK as follows.

0167407121020 N/O
0167408121023 N/C
Brass Body 1/8" BSP Taper thread provides good seal with a bit PTFE tape.

You can also use part nos

0166407281607 N/O
0166408281608 N/C
Stee body 1/8" BSP parallel will need a sealing washer. It is a bit cheaper than the brass one.


Hope this helps

Cheers Malc

PS. Don't pay them to set them up for you. Gently wind the adjuster screw inwards until you feel it tighten up (don't over-tighten) back off by 1 turn and you should be at 9 bar near as damn it. If your light is still on
unscrew adjuster 1/2 a turn at a time and test.

thanks for the info. Couple more questions:

1. where would I find this switch? Is it accessed via the compartment in the boot? or it under the car?

2. is the optional rubber cap with dual cable duct worthwhile getting? how would I know if I need this? Would the old one be perished?

3. my AYC light doesnt come on - but the pump was making odd gasping noises. After having the fluid replaced, the noise now makes a single squeeking noise every 20 seconds when driving. Does this sound like the pump is screwed, or would it be the pressure switch?

Thats a bit strange, was the correct fluid put in? Does the AYC function normally?

Thanks for the clarification Malc, much appreciated!

bradc said:

Thats a bit strange, was the correct fluid put in? Does the AYC function normally?

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yeh the correct fluid was put in. I dont really know if it functions correctly, I didnt want to push it too much with it making that sound. Fuse has been removed since the service (well since I got the car home after hearing that noise). Im pretty sure the bars were coming up as usual.

This thread has more details on my issue.

http://ozvr4.com/forums/showthread.php?t=1799

I think I will just buy the switch and see how we go.

Geeze Simon, that's not good news... Yes, start with the pressure switch, its by far the cheapest starting point.

Who did your bleed for you? If there's any air in the system you'll get noise like groaning and chatter in the pump. Long-term air in the pump will kill it just like any liquid pump (perhaps more so, as it uses the fluid for lubrication).

Hi All

If the AYC does go or play up? does anyone know where to pull the AYC fuse out to further prevent problems?

Am I on the right track here?


Thnaks
Jay

it is in the engine bay and the icon for it looks like a diff

there are 2 fuses.. one in the engine bay and one inside the cabin.. i think it's got this kind of icon

__
O__

i might be wrong though..

SiliconAngel said:

Geeze Simon, that's not good news... Yes, start with the pressure switch, its by far the cheapest starting point.

Who did your bleed for you? If there's any air in the system you'll get noise like groaning and chatter in the pump. Long-term air in the pump will kill it just like any liquid pump (perhaps more so, as it uses the fluid for lubrication).

Click to expand...

Who did the bleed Simon??

les haldane. I dont think he did a dodgy job, I think its just my ayc as it was giving me troubles before I had it serviced.

Just replaced my pressure switch today, but don't think I've fixed the issue - took it for a quick drive and got to three bars on right-hand turns and all good, first hard left corner = red AYC light. So thinking I may have air in the RHS chamber. I'll give it a bleed again when I can find an afternoon free and see if that fixes the it...