Can't fix the cruise control

[derpomz]

There is no light on the switch on the dash. Do i need a new ECU, whatever that is, Hoses seem ok. Fitted new Actuator,bellows, still nothing.

I have read about something under the dash near the drivers seat, any sugestions as to what this is and how easy it is to replace.

Im stuck guys as i an doing a long trip shortly and really would like to get it fixed.

I have since found that when i squeeze the bellows, i can hear air coming out, should this be so. Also i see at the back there are two, what look like hose inlets, with the bottom one with nothing connecting to it.

[PeterH]

The hoses are always the most likely culprits, when I was trying to get mine going, I pulled off the trim panels under the steering wheel, took the vacuum hose off the brake pedal switch and using my mouth, sucked air to create a vacuum in the hose.
If that holds, the hose is probably ok.
I connected a bit of vacuum hose directly to the bellows and was able to watch the bellows compress and hold using the same technique.
While you are in the footwell, carefully take off the vacuum switch and check that is working, it should hold vacuum and release when you move the switch in and out.
I had to replace mine, was only about $20 for that switch.
The light could just be a blown bulb, but could also indicate a faulty ecu.
Make sure the two short hoses on the bellows are sealing properly, poleonpom used cable ties to seal his properly.
There is a pretty easy electrical test you can do, you just need 3 wires with alligator clips on the end, I made some up very cheaply with bits from Autobarn.
Here's a link to an earlier post I did outlining this test:http://www.aulro.com/afvb/p38a-range-rover/195553-cruise-control-fixed.html
Hope that is of some help, or at least a starting point!
Good luck with it, Pete.

[derpomz]

When i got my P38 it had a new radio fitted. Could replacing the old radio effect the connections for the cruise control. I hear somewhere this could be a cause.

When i squeeze the bellows and hold my fingure over the bottom hole, this one has no hose on it, the bellows stays closed, take my finger of and it opens and air comes out.

I am trying everything i can think of.

[derpomz]

The hoses are always the most likely culprits, when I was trying to get mine going, I pulled off the trim panels under the steering wheel, took the vacuum hose off the brake pedal switch and using my mouth, sucked air to create a vacuum in the hose.
If that holds, the hose is probably ok.
I connected a bit of vacuum hose directly to the bellows and was able to watch the bellows compress and hold using the same technique.
While you are in the footwell, carefully take off the vacuum switch and check that is working, it should hold vacuum and release when you move the switch in and out.
I had to replace mine, was only about $20 for that switch.
The light could just be a blown bulb, but could also indicate a faulty ecu.
Make sure the two short hoses on the bellows are sealing properly, poleonpom used cable ties to seal his properly.
There is a pretty easy electrical test you can do, you just need 3 wires
with alligator clips on the end, I made some up very cheaply with bits from Autobarn.
Here's a link to an earlier post I did outlining this test:http://www.aulro.com/afvb/p38a-range-rover/195553-cruise-control-fixed.html
Hope that is of some help, or at least a starting point!
Good luck with it, Pete.

In the picture with the arrow, there are two like arms sticking out the back of the bellows. Should they both have hoses on them. Mine only has a hose on the top one, do you get what i mean.

[derpomz]

I think i see the problem. If the two pipes, thats what i call them, at the back of the bellows should have short hoses on them, then i am missing the bottom one, thats why i can hear air coming out when i press the bellows.

Where should the bottom of the two small hoses go. This could be my problem.

[derpomz]

Yes this is about my cruise again.

You must forgive me as a new owner, i dont know the name of the various parts, yet.

Underneath the bellows, that has the cruise cable and to which one of the small hoses goes, there is another little pipe thing thsat has no hoses going into it. It looks like a small sealed box of some sort, should bothe little pipe things have hoses connected to them. The top one is from the bellows things, but what about the bottom pipe, i guess you are as confused as i am but i cant think what else to call these two pipes.

I may have to give up and buy a Jeep.

[TheTree]

Hi Mate

Any chance you can post a pic?

Otherwise i could post a pic of my setup and see if we can identify the pipes

Steve

[derpomz]

Its not on the bellows, its that little box underneathe the bellows.

When i squeeze the bellows air comes out, is this right, or is there a leak in the bellows.

[clubagreenie]

A pic would help.

I don't know if it's the same as a D2 but one of my hoses fitted to a ver short, shrouded nipple and was split down inside the shroud and couldn't be pulled without tearing the hose. Had to completely dismantle the unit body (there's an abundance of very little in there) and I found that the seal between the body halves was damaged. It was leaking vacuum between the body halves (after fixing the hose). Got some straight o-ring rubber and made a new seal.

[TheTree]

Hi

Here is a pic of the way mine is connected and a pic from RAVE

Also do you have a copy of RAVE?

Steve

[PeterH]

The hoses in your photo look correct to me, the little white pipe underneath must be an outlet with no hose connected, mine is the same.
I would put cable ties at both ends of the two short hoses to make sure that is not the problem. That's where mine were leaking.

[Keithy P38]

Steve isn't the one with the issue Peter ;-)

[derpomz]

Thats how mine is connected. What is that yellow pipe with no fittings on it.

Should i be able to feel the air when i compress the bellows.

[TheTree]

Hi

I assume the pipe with no tube is some kind of exhaust, it looks the same in the pic from RAVE

When I compress my bellows I don't feel any air coming out where do you feel the air

Steve

[FANTOM P38]

Just to confer mine is same as photo , I think bottom pipe is some kind of vent.
I just replaced all hoses on mine from brake pedal to unit & small sections also. I bought 2 metres of vacuum hose from supercheap. I had previously replaced two small sections on bellows & i could still not get it to work.
I discovered when I pulled long section out that there was 2x splits about where it goes through firewall. For cost of tubing it is well worth peace of mind that possibility has been eliminated for some time.
Interestingly the new hose is same id but slightly larger od. Maybe Landrover were skimping here & this is why they seem to have common problem of breaking down ( wall thickness too small & gets brittle too easily)

[bruce p38]

Hi Phantom p38
did that sort the problem?

Bruce

[derpomz]

[QUOTE=SteveFarmer;2183867]Hi

I assume the pipe with no tube is some kind of exhaust, it looks the same in the pic from RAVE

When I compress my bellows I don't feel any air coming out where do you feel the air

Steve[/QU
Im not sure i can hear it coming out. Ive got a new bellows so im going to put that on to see if it makes a difference.

[TheTree]

Hi

According to RAVE the thing below the bellows is the vacuum pump so i guess the white tube is an inlet for that

If you don't have a copy of RAVE you can download a zipped copy from the link on this page

Range Rover Websites (http://p38.hts.com.au/rangie_websites.html)

Steve

[FANTOM P38]

Hi Phantom p38
did that sort the problem?

Bruce

Hi Bruce, problem solved - I've had a couple of goes at fixing in past but my focus was on end of hose near bellows as I could visually see cracking/splitting & just kept cutting back. My theory was that hose at this end is more exposed to under bonnet temps thereby more likely to be brittle, however I was surprised to find deep splits in two seperate locations close to where it penetrates firewall so if anyone else is having problems diagnosing faulty CC worthwhile checking this possibility or just replace complete hose as cost ,is minimal anyway & is very simple job 10 minutes to do.

[clubagreenie]

Did you use rubber or silicon hose?

[FANTOM P38]

Did you use rubber or silicon hose?
I just bought std vacuum hose from supercheap however when I placed side by side with oem hose I did notice significant difference in wall thickness.
OEM stuff is definitely thinner.

[bruce p38]

That's exactly what this forum all about Phantom,the collective mind
My mechanic and previous owner kept banging on ( in good faith I'll add) that it was the electrical controller under the dash that was faulty and after replacing three of them (them not me so an inherited problem )the system still didn't function so I'll try this on the weekend and hopefully get the cc going for the up and coming trip to croagingalong NP Like u I replaced hoses at bellows to no effect so thanks for that
Bp38

[derpomz]

Hi

Here is a pic of the way mine is connected and a pic from RAVE

Also do you have a copy of RAVE?

Steve

I notice that there are two hoses coming from the bottom of the bellows. Where does the the bottom hose of the two go, i cant seem to find where it connects.

[TheTree]

HI

If you look at the diagram I posted then it is pretty clear.

My bellows has one outlet and the tube loops from that to the vacuum pump. Just before the vacuum pump there is a T piece and the branch from there looks like it goes to the stuff in the drivers dash area

Steve

[FANTOM P38]

I notice that there are two hoses coming from the bottom of the bellows. Where does the the bottom hose of the two go, i cant seem to find where it connects.

Hi derpomz,
how did you get on? is it sorted now & what did you find, it may just help someone else!

[derpomz]

I have changed the Cruise Control bellows and put new hoses on them. I now have the light on the dash working but the controls on the steering wheel dont seem to be working.

Any help in this regard would be grateful, im having trouble understanding RAVE in this regard. Is something missing or is there a relay i should know about.

[Scouse]

Threads merged.


The bellows & hoses have no bearing on the light operation in the switch.
The light can be intermittent due to bad contacts or it could be something else but it's definitely nothing to do with your actuator (bellows) or hoses.