Pagoda SL Group
W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: charlie on June 24, 2009, 02:37:41
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In the technical forum it says use 5mm by 1mm o ring on the pump shaft but it also says at the end use a 5mm by 1.5mm does anyone know which is the correct sizing so i can order the correct fuel resistant o-ring. Any help will be appreciated. Cheers Charlie.
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I'd take that to read that there are two O rings of two different sizes. Get those two O rings and that would be a start.
I assume you are doing the early pump. It can be hard or next to impossible to get them leak proof.
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Yes it is an earlier pump. It's the taller pump. If i cant get it too seal does anyone know pricings for a new pump. Cheers
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Charlie,
The large pump can be successfully rebuilt so that it will not leak. The shaft rubber o-ring is a key part of the sealing. I will need to look to see what size o-rings I've been using for this, but what is more important than the stock size is the "sizing" that you must do to the o-ring once it is fitted to the shaft. As I recall, this step was not included in the Tech Manual and I have never been able to fit a stock o-ring, right out of the box and have it successfully seal the shaft. Essentially, what I do is to install a small o-ring--I'll find the size out for you later--onto the shaft. It needs to fit very tightly so that it does not slip during the "sizing" process which follows. After fitting the o-ring, chuck the armature assembly into a drill press with the seal side down. Try fitting the bellows seal onto the shaft with the grooves facing downwards w/o forcing it. It should not at this point slip past the o-ring. Remove the bellows and turn on the drill press while holding some fine sandpaper against the rubber o-ring to sand it down and reduce its outside diameter so that the bottom of the bellows just slips past it. This is a trail and error process and you may have to repeat it several times until the bellows slips past it. The key is not to force the bellows on, yet when it does go past the o-ring you want it to lodge tight against the top (grooved) portion of the bellows--the inside the holes on both ends of the bellows are of slightly different diamters- this is how you ensure a fuel tight seal in this area.
George Des
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Also, a very, very small point on rebuild. I think the o-rings on the rods that hold the top bearing housing go on the outside--- housing, o-ring, washer, nut. Rebuild says they go on the inside. ???
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when I took the motor end cap off, the o-rings were on the inside.
I reported what I found.
I used the 5mm x 1 mm o-ring because it was a perfect replacement for the broken one on the shaft and did not need to 'sized' to allow the bronze seal to fit over it.
the article was written as a guide.
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thanks all, managed a successful rebuild. Resized the o-ring with sandpaper & it worked well. Thanks for all your help & advise. Cheers ;D