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Just tried out my new WP/PDS vacuum pump......


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Just a quick thank you to my friend George who built me a new WP vacuum/pressure pump to fill PDS shocks.:banghead:

Man what a time saver this will be. Its small enough to mount in my trailer so I can use it at the tracks. I can see now why all the hype on why this is really the only/best way to build these shocks correctly.

I just built 2 shocks for Jacqueline Ross (as she's getting ready to defend her title in Canada) in less time than I could do one by hand.

doc

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Just a quick thank you to my friend George who built me a new WP vacuum/pressure pump to fill PDS shocks.:banghead:

Man what a time saver this will be. Its small enough to mount in my trailer so I can use it at the tracks. I can see now why all the hype on why this is really the only/best way to build these shocks correctly.

I just built 2 shocks for Jacqueline Ross (as she's getting ready to defend her title in Canada) in less time than I could do one by hand.

doc

I think its a must for a serious syspension shop.You can built now the shock faster and ....clean of oil...!!:banghead:

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Just a quick thank you to my friend George who built me a new WP vacuum/pressure pump to fill PDS shocks.:banghead:

Man what a time saver this will be. Its small enough to mount in my trailer so I can use it at the tracks. I can see now why all the hype on why this is really the only/best way to build these shocks correctly.

I just built 2 shocks for Jacqueline Ross (as she's getting ready to defend her title in Canada) in less time than I could do one by hand.

doc

Try bleeding one by hand and then use your bleed pump to see how much more air comes out. I did this and was blown away how much more effective it was.

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Just a quick thank you to my friend George who built me a new WP vacuum/pressure pump to fill PDS shocks.:banghead:

:banghead:

glad to see you joining the 'vacuum pump users club' :banghead:

Man what a time saver this will be. [...] I can see now why all the hype on why this is really the only/best way to build these shocks correctly.

and the good thing is, with the correct adapters you can use it for the other shocks as well :banghead:

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built mine for around $100

I just saw a vacum pump at a yard sale for about 90bucks. I noticed it would pull 30 in. vacum(that number rung a bell). But I was not sure if the thing would work. I have no idea what to buy/build even after reading posts on TT and the Talk.

So, how much for a "built kit" fgkell?:banghead: Must do Jap shocks too:thumbsup:

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I'd be happy to share with anybody. I won't take any credit for the design, as others on this site came up with the basic design. I just made mine less expensive using locally available parts and a modified bycicle pump for vacuum.

P3190141.jpg

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Hey shockdoc...

How about posting a picture of your setup? Its always interesting to see what others do.

Has anyone tried using one of those cheap Harbor Freight venturi type vacuum pumps? It would be a bunch cheaper than any of those rotary vacuum pumps.

http://www.harborfreightusa.com/usa/itemdisplay/displayItem.do?itemid=96677&CategoryName=&SubCategoryName=

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Hey shockdoc...

How about posting a picture of your setup? Its always interesting to see what others do.

Has anyone tried using one of those cheap Harbor Freight venturi type vacuum pumps? It would be a bunch cheaper than any of those rotary vacuum pumps.

http://www.harborfreightusa.com/usa/itemdisplay/displayItem.do?itemid=96677&CategoryName=&SubCategoryName=

Ooooooo, I love Harbor Freight, got one just down the road ...

edit: I just spotted this pump in the link above that pulls 28.3" vacuum on ebay for $17.00!! Must be hooked to a compressor of course.

I must be missing something here:bonk:

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OK, I just read this https://thumpertalk.com/forum/showthread.php?t=691899

If you have the time fgkell, perhaps you could explain how yours work and a parts listing.Something simple would be enough:worthy:

I can make the reservoir adapter on my lathe for the jap shocks like Drehwurm

has done and pull vacuum from one of my intake ports of my compressor or buy something cheap on ebayy.

You must have reversed the mountain bike pump piston, to pull vacuum?

Seems most of the good parts links from the thread above are dead.

I like blue vacuum.jpg

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Will an HVAC vacuum pump work for this project. My brother has one he said he will give me. I'm pretty sure it'll pull more vacuum than I need but hey if it'll get me started:busted:

Plug it in to AC power and voila:banana:

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many cheap 12V 4wd compressors pull a good vacuum, teflon rings and no sump oil to get pulled past the rings.

just need to make sure you can hook up to the inlet easily

Did not think about blow-by(rings). I need a schematic/instructions and more research.

Ebay has some good deals on HVAC pumps. Perhaps that route would be a lot easier than my compressor. Less hose laying about the shop:thumbsup:

Or the 12 volt compressor sounds good too. How much vacuum can a 12 volt system pull?

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OK, I just read this https://thumpertalk.com/forum/showthread.php?t=691899

If you have the time fgkell, perhaps you could explain how yours work and a parts listing.Something simple would be enough:worthy:

Pretty simple really. The reason I set it up with it's own reg is so I can just plug shop air into it without adjusting my compressor down to the 40psi I wanted at the resevoir. between the reg/filter and the resevoir is a two way ball valve to switch between pressure and vacuum. At the bottom of the resevoir is a line to shock with a return line to the top of the resevoir. Check valves direct fluid from the bottom of the resevoir under pressure and to the top under vacuum. Although the cheap check valves don't work so hot and I'd like to have the return line closer to the shock so there is a revision in order. I'll either order some nicer check valves or simply use manual valves mounted at the rezzy. Drehwurm, I believe posted links for some nice check valves but they aren't available in the U.S. and would be very expensive to ship here. Haven't been able to find a cost effective alternative. Anybody have some ideas or links to share would be appreciated. I would also love to incorperate a quick coupler into the mix. Norgren makes a fitting with 1/8G threads on one end and hose barb on the other but again, not available in the U.S.

You are correct, I reversed the piston in my bike pump and removed the check ball, attached a suitable line for vacuum witha check valve in reverse direction and have no problem pulling 25"hg. I'm still in the market for a chep way to get to the 29"hg mark but the bike pump is working quite well for now.

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MRW,

I think we are in the same boat. I'm having a hard time picturing how

this setup works.. I need a schematic diagram, parts list and

a description of operation. eg. do you fill the "oil tank" with fluid, then pull vacuum from the "oil tank" to the fill the shock or vice versa or neither?

Do we fill the shock with oil, pull vacuum on the shock, to fill the "oil tank"

and pump the degassed oil back into the shock?

Here is what I have thus far. 120 volt vacuum pump and old water filter for an oil tank.

I know I need hoses, fittings, and a bleed apparatus for the shocks, I'm totally loss when it comes to that.

Thanks for any help!

jwaseman

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MRW,

I think we are in the same boat. I'm having a hard time picturing how

this setup works.. I need a schematic diagram, parts list and

a description of operation. eg. do you fill the "oil tank" with fluid, then pull vacuum from the "oil tank" to the fill the shock or vice versa or neither?

Do we fill the shock with oil, pull vacuum on the shock, to fill the "oil tank"

and pump the degassed oil back into the shock?

Here is what I have thus far. 120 volt vacuum pump and old water filter for an oil tank.

I know I need hoses, fittings, and a bleed apparatus for the shocks, I'm totally loss when it comes to that.

Thanks for any help!

jwaseman

The tank/resevoir is filled with more than enough oil to fill your shock body. The shock is assembled dry. The resevoir is pressurized, forcing fluid into the shock. then the resevoir is vacuumed and the fluid is pulled from the shock. This cycling allows the shaft to extend and retract causing fluid and air to flow in and out. Under vacuum, the air in the fluid is expanded causing it to easily flow to the top. The check valves in the line serve to send the fluid/air from the shock back to the top of the resevoir while keeping the fluid being sent to the shock free of bubbles.

So the process is simple.

Step 1. Fill shock body

Step 2. Vacuum to degas fluid and flow air/fluid from shock

Step 3. Repeat until no air comes out.

If it still doesn't make sense, consider sending your shock to a proffessional.

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