Suspention pump

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hangman3
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Suspention pump

Post by hangman3 » Sat Sep 16, 2017 3:48 pm

I am about to embark on the job of re-building the air pump & dryer but don't have the parts yet. I went to take the cover off just to take a good look so I would have a better idea when I actually start the job & the first bolt I turned in the centre of the cover snapped off (great start). I have not bothered with the others yet as I don't want to be driving around with the pump exposed while I wait for the parts to turn up.
Question: Are the other two likely to snap off as well & how easy is it to get to their bases to get the rest out when the cover is off? Also, what kind of job have I set myself up for, is the start a good example of how the job is going to go?



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anglefire
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Re: Suspention pump

Post by anglefire » Sat Sep 16, 2017 9:29 pm

I tried to rebuild my compressor some years ago. Ended up getting a new one. :shock:


Bolts that hold the bracket onto the chassis are no biggy as you can get new ones and their corresponding captive nuts easily enough. In fact, I would recommend replacing them regardless.


Mark

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Re: Suspention pump

Post by PillowSmuggler » Sun Sep 17, 2017 4:58 pm

As Mark says the addition of replacement mounting bolts and captive nuts is a must. I also heavily coat those bolts with copper-slip to help get them out again afterwards as they really do seem to suffer from corrosion for some reason, but once out they are easy enough to replace.

I actually have two pumps, so I can use a full rebuild kit on the spare and then put it ready on the shelf for the next time.
My pumps have been rebuilt several times, some of the online kits are very full and allow you to replace even the o-rings in the air pipe push fit connectors. The time it takes varies massively depending on how bad the corrosion is; Quickest rebuild was around 2 hours (not knocking myself out) and longest was about a week as I struggled to get the crank bolt out and didn't want to completely kill everything with the by then very tempting 4lb lump hammer. The torx socket rounded out without the bolt shifting so I had to use a Dremel to cut a slot for a wide flat screwdriver blade and had to use a mini cold chisel to shock it loose. This cannot be done without the special block and collar that stop the piston being damaged, so make sure your kit has these in it. I think this is the hardest thing I had to work on; everything else is straight forward

You will need some silicon sealant to refit the crank plate cover; I use the stuff from Hobby stores they use for paper craft as it's acid free; bog standard silicon gives off acetic acid (vinegar) and that's not a happy thing to put near aluminium.
My spare pump originally had a vital washer missing between the cylinder part and the main body; I had water / mud inside the crank housing and it took some heavy cleaning and some silicon sealant to make that water-tight again. The washer itself is very very thin and so easily lost; work in a clean area and beware the springs and that shouldn't happen to you :lol:

I've also taken to using silicon brake grease sparingly on the threads of the various bolts to reduce wear and try and keep the water at bay to try and reduce the corrosion of the aluminium - jury is still out on whether that's working. Finally some brake cleaner spray is a must as there must be absolutely not a single jot of grease in the cylinder bore or on the piston seal; I clean and de-grease everything well before re-assembling.

Just for reference, the last refurb kit I bought was this one, which also includes a new relay (another must), the replacement aluminium o-ring that holds the new piston seal onto the piston top, and as the top of my drier had also started to crack this kit also includes an aluminium replacement too : http://www.ebay.co.uk/itm/282534764941" onclick="window.open(this.href);return false;

There are plenty of you-tube videos showing how to rebuild these pumps; a couple of hours reviewing these with a beer or two will save lots of stress when doing the job itself, but biggest tip is to make sure the piston isn't damaged in any way; it's made of very thin and soft aluminium so removing the old seal needs a lot of care :thumbright:


Regards, Dom.
2007 HSE Auto TDV6
Snorkel, Cyclonic air filter, GNVP Rock Sliders
78Ah Aux, Split charge, FBH Timer/Remote, Mantec sump plate
LED: Strobes, interior, camping, brake, running, sides
New Oil Pump, using 2SO at 1:400.

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hangman3
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Re: Suspention pump

Post by hangman3 » Mon Sep 18, 2017 10:01 pm

As it turns out I had already bought the same kit from the same dealer but without the relay (I had already got one of those last week when I got the delivery valve.
Cheers for the info, I will get back when the job is done to say whether I swore a lot or if it went well. Fingers crossed.



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hangman3
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Re: Suspention pump

Post by hangman3 » Tue Sep 19, 2017 8:02 am

Question??

I keep seeing that it is important to replace the relay when you do this job or it will cause problems or damage if you don't.

What problems/damage can it cause?

Also, not having seen this warning earlier, the relay that I bought to replace the old one I fitted when it arrived. Do I now have to buy another one as this one has been used for about 100ml?



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Re: Suspention pump

Post by PillowSmuggler » Tue Sep 19, 2017 9:39 am

From what I understand it's because the older a relay gets the more the contacts wear and so the higher resistance it builds up. This simply makes less volts available to the pump which then has to draw more amps to get the job done, so more heat, more stress and runs for longer (lower volts == lower speed). An old relay can therefore cause a new pump to fail quicker, and this is especially so if the contacts melt and fuse and run the compressor until the battery goes flat.

I'd not worry about a few hundred miles on the relay; I'd consider that to be still new for all intents and purposes.

I've never figured how these relays can drop volts without catching fire (1 volt at 40 amps = 40 watts of heat which is more than most soldering irons) but they do seem to manage well!

Good luck with the overhaul :thumbright:


Regards, Dom.
2007 HSE Auto TDV6
Snorkel, Cyclonic air filter, GNVP Rock Sliders
78Ah Aux, Split charge, FBH Timer/Remote, Mantec sump plate
LED: Strobes, interior, camping, brake, running, sides
New Oil Pump, using 2SO at 1:400.

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hangman3
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Re: Suspention pump

Post by hangman3 » Tue Sep 19, 2017 7:58 pm

Have now completed the rebuild. It all went surprisingly well. the hardest part was getting off the almost 17mm bolt that holds the delivery valve. Tomorrow it wil get put it back on the waggon after I visit Matford LR to get the new captive nut things for the chassis. I suppose I cant test it until its on the car, so I hope its all OK as during the job, there was nothing obvious to see really.



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hangman3
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Re: Suspention pump

Post by hangman3 » Wed Sep 20, 2017 3:04 pm

Any suggestions on the easiest way to put in the top bolt?? :headbang: :headbang:



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anglefire
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Re: Suspention pump

Post by anglefire » Wed Sep 20, 2017 4:36 pm

Bendy arms. :roll:

It's possible with a flexi ratchet spanner from memory.


Mark

Waeco CFX 40
1977 Triumph Spitfire 1500
Skoda Enyaq IV 80
Skoda Superb SE L Ex (Gone)
2006 disco3 SE. Gone but not forgotten.
BMW 530d M Sport Touring. Gone
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PillowSmuggler
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Re: Suspention pump

Post by PillowSmuggler » Wed Sep 20, 2017 6:32 pm

It's not easy, especially if you're blessed with big hands :(
Something like this can be useful, though I don't know what size those bolts are off the top of my head so this is just an example from a random supplier :
http://www.ebay.co.uk/itm/132251423915" onclick="window.open(this.href);return false;


Regards, Dom.
2007 HSE Auto TDV6
Snorkel, Cyclonic air filter, GNVP Rock Sliders
78Ah Aux, Split charge, FBH Timer/Remote, Mantec sump plate
LED: Strobes, interior, camping, brake, running, sides
New Oil Pump, using 2SO at 1:400.

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