Member Since: 04 Oct 2016
Location: Hampshire
Posts: 2406
Dropping.............
Generally my D3 drops on 3 corners . About 5 to 10mm over a 24hr period. OSF stays up. Have pulled the fuse and it drops more on the rear. Upon starting it rises quickly, maybe 5 to 10seconds if left for a week. A little longer if left longer. Hence its on the list to do but with no real urgency.
Unable to find any leaks. Front and rear valves rebuilt. Put new front structs on (no reason but they were GVFM so hey ho) and did DM's clamping air lines proceedure but cant remember what the conclusion was. (I think the rear still dropped but I was going to change the rear structs to match so wasnt too worried). Also did Gary's pushfit conversion which makes things somewhat easier.
I came to the conclusion that the valve blocks were bypassing air and was going to replace these. However I've noted on the last two occasions, when left in normal height, that the front (both sides now) is dropping and the rear is staying up. Just put the car into access mode as it was looking a bit like a drag car
So I'm now back scratching my head.... any ideas / advice?
20th Dec 2020 9:02 pm
Globetrotter448
Member Since: 21 Mar 2017
Location: Londonderry NSW
Posts: 1772
When doing the valve blocks you did replace "all" O rings including the small one on the centre valve. If you did then it is more likely that you have a leak on one of the connections. This vehicle is parked on level ground otherwise it will try to self level.
25th Dec 2020 11:02 pm
pjm-84
Member Since: 04 Oct 2016
Location: Hampshire
Posts: 2406
I've done the small o ring. Both valve blocks were clean but are cleaner now. Connectors, including top of structs, are all changed to push fit following Gary's tip. (Much easier). Sealed and tested for leaks at the suspension side of the valve block. All good. Front structs are new. Rears are still original.
I need to check how it drops again.
I havent done the central valve block but I'm not sure if this would cause an dropping issue as its the otherside of the front and rear valve blocks.
26th Dec 2020 9:47 am
Kviasen
Member Since: 24 Dec 2020
Location: Norway
Posts: 107
The center valve block only controls filling and when to add air from the reservoar to the gallery fks when raising to off road mode as a boost reserve.
The gallery pressure valve is also placed in the center block.
If there is a leakage the normal problem is the air bellow or seals to the respective strut, connections or the plastic feed pipe.
Valve blocs for the 2 front and 2 rear wheels seldom has internal leakages even when noumorous people take them out for a clean up and why not it dosent hurt.
27th Dec 2020 8:09 pm
pjm-84
Member Since: 04 Oct 2016
Location: Hampshire
Posts: 2406
Currently raised / pulled fuse 26 and will monitor the drop. Sprayed the connectors to the structs (dropping corners) and no leaks. Might put on a set of new rear structs once the weather warms up and hold fast on the valve blocks.
27th Dec 2020 8:27 pm
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13576
pjm-84 wrote:
I've done the small o ring. Both valve blocks were clean but are cleaner now. Connectors, including top of structs, are all changed to push fit following Gary's tip. (Much easier). Sealed and tested for leaks at the suspension side of the valve block. All good. Front structs are new. Rears are still original.
I need to check how it drops again.
I havent done the central valve block but I'm not sure if this would cause an dropping issue as its the otherside of the front and rear valve blocks.
Hiya
Glad those push fits made life easier , biggest difference was when trying to refit the rear valve block for ease
If it helps in any way I used a hand vacuum pump to test the air valve blocks to ensure they weren't letting by using One of these , so at least then u know 100% are sound
Link below I found better than the cheaper vacuum pumps , plus bought got some 6mm plastic pipe , along with assorted pushfit fittings , isolating valves etc
Can also use the vacuum hand pump testing different lines of the suspension system, at one time I pulled out the connecting pipes going from the reservoir valve block to the rear to find there was a big drop
Alas , had to move onto bigger testing rigs because I had to start pressurising the struts one by one as the hand vacuum pump wasn't man enough
Hope that may help
27th Dec 2020 8:35 pm
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13576
This is what I made up in the end , including using the oil extractor vacuum pump, tyre inflator , blanking off pipes so could test from one end to the other , suspension system had more leaks than a colander
Before I forgot , also got one of those garden sprayers seeing it had a long Lance and was ideal spraying soapy water onto the top of the strut connectors to test for leaks
Hope it’s an easy fix
27th Dec 2020 8:51 pm
pjm-84
Member Since: 04 Oct 2016
Location: Hampshire
Posts: 2406
Thanks Gary, going to order one of those.
Yep the rear valve block is a 5min removal job once you have the wheel off. The push fits are great.
27th Dec 2020 9:02 pm
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13576
Ur so welcome and found it invaluable , even used it testing the air tank as just pulled the pipe off the reservoir valve block
One thing I did do before using it was fitting a cap on the end, pulled a vacuum and watched the gauge to ensure that was working perfectly first before using it
Indeed ref that rear valve block , particularly the back pipe connection using those push fits
Plse let us know how things go
27th Dec 2020 9:34 pm
defector
Member Since: 23 Feb 2009
Location: Greater Manchester
Posts: 1419
gstuart wrote:
This is what I made up in the end , including using the oil extractor vacuum pump, tyre inflator , blanking off pipes so could test from one end to the other , suspension system had more leaks than a colander
Before I forgot , also got one of those garden sprayers seeing it had a long Lance and was ideal spraying soapy water onto the top of the strut connectors to test for leaks
Hope it’s an easy fix
GStuart, when NASA are missing a special tool while servicing their Super Heavy Lift Launch Vehicle, do they ring you direct to borrow yours?
28th Dec 2020 12:42 am
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13576
Sssshhhhhhhhhhh , it’s a big secret that I’m on there payroll
28th Dec 2020 12:47 am
pjm-84
Member Since: 04 Oct 2016
Location: Hampshire
Posts: 2406
Okay, interesting. The low drop measured back in the summer has somewhat changed.
Over an 15hr period I lost 50mm on the NSF, 30mm on the OSF, 5mm on the NSR (probably from the dropped NSF) and gained 10mm on the OSR. (as a result of the dropped NSF)
The OSF didnt leak back in the summer. Now it lost 30mm? Going to order a replacement front valve block.
28th Dec 2020 10:21 am
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13576
Hiya
All good fun, lol, had this as well ref the air valve blocks , sometimes they would seal other times they wouldn’t , think that was down to the silica that had completely broken down to a fine dust from the drier
Would be interesting if ur able to get that hand vacuum pump at the same time , as with the old valve block and new one side by side off the disco u could test them and ur see straight away of the difference,
Also with the vacuum hand pump Ur be able to see which port on the old valve block isn’t sealing properly
Alas in the end I ended up replacing
Compressor
Both front struts
Air tank
3 x air valve blocks
Sections of tubing
Replaced virtually all the voss connectors with the push fit ones , also as a side note I still can’t get over how expensive those voss connectors are
Plus don’t think it helped by seriously being neglected by previous owners who had done bodge after bodge, took me nearly a year to sort the entire disco out from multiple lash ups , right down to fitting the correct screws and fixings , removing old rounded off bolts and fitting new stainless steel ones
Yeh i know , I need to get out more
After I had sorted out the entire suspension system the difference was amazing with how it drove
Sorry I’m gassing again, lol
Hope ur new air valve block resolves all the issues and please let us know how things go
28th Dec 2020 7:53 pm
pjm-84
Member Since: 04 Oct 2016
Location: Hampshire
Posts: 2406
Just swapped out the front air valve block.
Old air valve block started making gurgling noises once I switched the vehicle off.
1st Jan 2021 4:24 pm
pjm-84
Member Since: 04 Oct 2016
Location: Hampshire
Posts: 2406
All sorted. Replaced front and rear air valve blocks so no more dropping. No longer recognize the Discovery after a few days because its still up on its haunches.
Push fit on the rear air block was a little tricky as its exposed to the elements.
Rebuild with seals didn't cure the issues with either air valve block. I suppose at 16yrs replacement was long overdue.
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