D1 cruise control vac pump

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discofiremedic

Guest
Has anyone here ever fixed a cruise control vac pump? I don't know for sure that's my problem. In the past I've fixed the old cracking vac hoses but now they look fine. On the side of the vac vump there is a flat oval-shaped cover that you can pry out with a flat-blade screwdriver. This access cover seems to be sealed with a white-colored o-ring (an oval ring actually) but in my case the ring is broken and about a one inch section was missing. I'm guessing that if I can find a replacement that this may solve my problem.

But where to find a replacement??

Or maybe I run a tiny bead of silicone cauling along the seat area and hope for the best?? I see new vac pumps listed at $425!:rofl:

I'll look forward to any replies and will let you know if my cheapo fix works.
 
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ebrown

Guest
Please let me know if the cheap fix works, I think that I have a vac pump problem also, but I'm not sure.

If it wasn't the vac pump, what else could it be? My switch looks good, fuse looks good, anything else?

Sorry, not trying to hijack your thread, PM me if you'd like.
 
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Rovermike

Guest
if all else is good, probably an ECU problem, seems to be a rampant problem on D1's
 

jcs2179

Well-known member
Jan 23, 2006
665
0
Illinois
W. Tillery can hook you up with a very decent used pump for cheap...(and ECU too). Drop him a line. Not worth messing with the old one.
 
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discofiremedic

Guest
I have silicon-caulked my vac pump and let it cure for the day. Got side-tracked on non-Rover issues for most of the day. Actually got hung up on some damn Dodge Dakota electronic choke trial and error repair. But that's another story.

Just checked my little vac pump unit and its looks good, I'm optimistic, will re-install tomorrow and let you know. If this doesn't work feel free to hijack my post and we'll troubleshoot tpogether on down the road from there.
Thanks!
Dave
 

witty.names

Member
Aug 8, 2006
10
0
I don't have a disco 1 here to check, but i remember that it looked like the same pump as a late volvo 740. If it is, you can get those in the bone yard around here for $10.
 
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ebrown

Guest
hmm... sounds like a little fun at the pull-a-part tomorrow...
 
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Rovermike

Guest
How did you get your vac pump out. I dont see an easy way to get to mine. Its under a metal plate where the jack would be, my jack is missing, I can look thru some oval holes at it, but dont see an easy way to remove it. Mike
 

MNSUROVER

Active member
Apr 28, 2004
38
0
Viroqua, WI
I was having issues with my pump as well and was able to fix it. There are two nipples coming off a diaphragm at the end of the pump, (one splits the other is straight, I think). At the base of each nipple is a one way valve. One only lets air in the other only let?s air out. In the case of my pump I found that one of the valves was stuck so it would not pump. I could tell by trying to suck or blow on each of the lines to the diaphragm. One only allowed air out the other would go both ways.

Not that I can recommend doing this but to fix mine I used a 9 volt battery across the terminals to make the pump run then stuck the suction hose into a glass of water. It took a little bit to get the pump to prime but when it did dirt came out with the water the first few pumps then it started to pump water pretty steady. Then I ran it dry and checked the valves by blowing into them and both worked. Since then the pump has worked fine.

It has been awhile since I have done this though so I can't remeber which terminals I went across with the battery. You might be able to see by looking behind the oval cover. One connnects to a relay to close a valve, one connects to the pump and the other is ground with both connected to it. The 9 volt worked good since the battery terminals lined up with the connections on the pump

Jan
 
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discofiremedic

Guest
That is a pretty cool idea about how to clear the vac pump. Which I may have to try since my cheapo silcone caulking attempt did not do the trick.

Someone in one of the replies asked how to get out the pump. That would be by wiggling it upwards. It mounts to the sheetmetal via three little rubber "thingies". No bolts. Getting it out is easier than getting it back in. To get it back in you have to start the cone shaped rubber thingie into the hole then grab it from the other side with a pair of needle nose pliers or something and pull ever so gently until they seay past the little retainer groove.

Thanks for all the replies. I thinkI'll have to do a little more diagnostic before I'm ready to say "look MA, I'm driving with no feet on the gas pedal!"
Dave
 

Phototone

Well-known member
Apr 8, 2008
87
0
Van Buren, Arkansas
The oval cover does not have to be air tight for the pump to work. The whole "pumping" action of the pump is done on the outside, where the main hose connects. The hoses running around to the back side near where the electrical plug are for 2 purposes. One hose goes to the internal solenoid. This solenoid closes and plugs the end of this particular hose, which should run up to the outside of the unit and "T" into the vacuum fitting where you install your long hose that goes to the servo unit and brake switch. The other hose which is tee'd into the side of the pump goes to the air outlet port on the outside of the pump, which looks like it should also have another hose attached to it, but doesn't.
 

skullanova

Member
Feb 11, 2008
15
0
Hey, great thread with some cool ideas(9v). Not to steal thread but just wondering exactly what your symptoms have been. I seem to have cc about 60 % of the time, have changed all hoses. Also will work fine than just kick out on me, just pissing me off. Thanks
 

Phototone

Well-known member
Apr 8, 2008
87
0
Van Buren, Arkansas
I'm also having intermittant issues with the cruise control, and I believe it is the ECU. I have ordered a guranteed "salvage" unit for a reasonable price to try. It could also be the cut-out relay...
 
Phototone said:
I'm also having intermittant issues with the cruise control, and I believe it is the ECU. I have ordered a guranteed "salvage" unit for a reasonable price to try. It could also be the cut-out relay...

Have you checked the switches and the relay? They are much more prone to failure than the ECU-even though your truck is a '94 with somewhat elevated mileage, I would have investigated further before buying a boneyard ECU.
 

Phototone

Well-known member
Apr 8, 2008
87
0
Van Buren, Arkansas
I have checked and verified all the switches work well, the dash switch, the clutch and brake cruise switches and the steering wheel switches. i dont know which relay is the one for the cruise control. If someone can give me a location pointer, I will check that.
 
The cruise relay is the only black relay on the bracket beneath/behind the glove box. It is not a standard "Ice Cube" relay. For some reason, the engineers at Rover decided that it was a good idea to run stupid current through it, thus two of the terminals are HUGE! It's the only black one under there, it has a huge brown wire running to it.

On my Disco, I have so far replaced everything but the switches (but, the set switch now does nothing, the other one does the setting as the set part wore out) and the ECU. It's a trail rig only now so I don't exactly need cruise any more though. The switches wore out around 180K miles and the relay right around 200K.
 

Phototone

Well-known member
Apr 8, 2008
87
0
Van Buren, Arkansas
ptschram said:
The cruise relay is the only black relay on the bracket beneath/behind the glove box. It is not a standard "Ice Cube" relay. For some reason, the engineers at Rover decided that it was a good idea to run stupid current through it, thus two of the terminals are HUGE! It's the only black one under there, it has a huge brown wire running to it.

On my Disco, I have so far replaced everything but the switches (but, the set switch now does nothing, the other one does the setting as the set part wore out) and the ECU. It's a trail rig only now so I don't exactly need cruise any more though. The switches wore out around 180K miles and the relay right around 200K.

Is this the relay that has the cruise control diode in the wiring harness to the relay?