Does anyone know how to build an injector tester?

bertcarrier · Post by **bertcarrier** » Tue Jan 15, 2008 8:25 pm

Can anyone give guidance on how to build a reasonably priced injector tester? I seem to remember Hagar or Vincent Waldon (both superstuds by the way) talking about it.

Thanks!

jason · Post by **jason** » Tue Jan 15, 2008 9:09 pm

There is one here, http://www.vwdiesel.net/phpBB/viewtopic.php?t=2828

Vincent Waldon · Post by **Vincent Waldon** » Tue Jan 15, 2008 9:11 pm

I've built one but haven't rushed out to publish a HOW-TO since diesel at that pressure is dangerous to the point of being potentially lethal, particularly if you scrimp on the materials.... hard to control what people do with HOW-TOs...

Having said that though, here's a great thread on the topic:

http://www.vwdiesel.net/phpBB/viewtopic.php?t=2828

(edit.. great minds think alike !)

Please please please heed the warnings... !!

Vince

bertcarrier · Post by **bertcarrier** » Tue Jan 15, 2008 9:14 pm

Oh man..

That is too freakin' cool. I'm making one!!

Post by **Fatmobile** » Wed Jan 16, 2008 2:51 am

I went through my pile of bottle jacks and found a 5 ton that was froze up.
I broke it and fixed it, got it apart and today I made the piece of metal to weld to the top... spot welded it on and intend to take it to a friend with a bigger welder and certification.
Andrew sent me a link to an ebay gauge that is 12" across. I'm going to use a gauge from a cutting torch regulator for now but some day I'll have a big, fat gauge on it.

duffer · Post by **duffer** » Wed Jan 16, 2008 12:48 pm

I have a couple of questions...

I've never taken a bottle jack apart before.
so, how do you replace the outer jacket once
the steel plate is welded on? Does the inner
tube unscrew from the base?

And...

Where do you get high tensile steel fittings (Tee)
with 1/4" NPT thread for the top? (I don't trust
the brass ones).

Thank you for any information you may have.

Vincent Waldon · Post by **Vincent Waldon** » Wed Jan 16, 2008 1:05 pm

duffer wrote:I have a couple of questions...

I've never taken a bottle jack apart before.
so, how do you replace the outer jacket once
the steel plate is welded on? Does the inner
tube unscrew from the base?

And...

Where do you get high tensile steel fittings (Tee)
with 1/4" NPT thread for the top? (I don't trust
the brass ones).

Thank you for any information you may have.

On most bottle jacks the ram tube treads into the bottom of the bottle jack.. so you unthread the ram tube, get the top welded on, and then thread it back on with the outside attached.

You're a wise man to avoid standard brass plumbing fittings for this job... in my mind if you are in the plumbing isle at any time when building this device you're taking your life in your hands !!

In terms of the high strength fittings: I find the best spot is a store that sells hydraulic fittings. Specifically for us Canadians Princess Auto has everything you'll need, including a cheap (although not particularly large) 3000 psi gauge for 10 bucks.

Well, almost everything... you'll need to round up a diesel hi-pressure line to cut apart.

The 10 dollar 4-ton Princess Auto bottle jack works perfectly as well, btw.

duffer · Post by **duffer** » Wed Jan 16, 2008 2:23 pm

Vincent Waldon wrote:
duffer wrote:I have a couple of questions...

I've never taken a bottle jack apart before.
so, how do you replace the outer jacket once
the steel plate is welded on? Does the inner
tube unscrew from the base?

And...

Where do you get high tensile steel fittings (Tee)
with 1/4" NPT thread for the top? (I don't trust
the brass ones).

Thank you for any information you may have.
On most bottle jacks the ram tube treads into the bottom of the bottle jack.. so you unthread the ram tube, get the top welded on, and then thread it back on with the outside attached.

You're a wise man to avoid standard brass plumbing fittings for this job... in my mind if you are in the plumbing isle at any time when building this device you're taking your life in your hands !!

In terms of the high strength fittings: I find the best spot is a store that sells hydraulic fittings. Specifically for us Canadians Princess Auto has everything you'll need, including a cheap (although not particularly large) 3000 psi gauge for 10 bucks.

Well, almost everything... you'll need to round up a diesel hi-pressure line to cut apart.

The 10 dollar 4-ton Princess Auto bottle jack works perfectly as well, btw.

libbybapa · Post by **libbybapa** » Wed Jan 16, 2008 2:30 pm

IMO, the easiest fittings to deal with that are properly rated are steel flare fittings. Unfortunately, I doubt you will find any in the 45Â° flare. Any that I have been able to find that would fit the injector line are 37Â° flare which requires the purchase of a 37Â° Flare tool. The 37Â° flare tool is also a specialty tool and somewhat hard to locate inexpensively.

Andrew

duffer · Post by **duffer** » Wed Jan 16, 2008 2:44 pm

Oops, sorry about that.

The thing is, I'd prefer to keep all of my extremities.
And my wife would be somewhat disappointed were I
to lose any of my naughty bits.

Amputation isn't an option.

I was just leafing throught the Princess Auto catalogue...
The have a glycerine-filled (to "reduce erratic needle
movement") press. gauge rated to 5000 psi for $14.99
and a 4-ton bottle jack for $19.99 both of which should
suffice.

They DO have hydraulic fittings, but unfortunately they don't
indicate what the pressure ratings are.

I'll have to go in and ask.

In the interim, thank you for the information.

Vincent Waldon · Post by **Vincent Waldon** » Wed Jan 16, 2008 4:28 pm

I was able to find a 3000 psi version when I was there... it's not the biggest of gauges so if you are shooting for accuracy you'll have more scale with a 3000 psi gauge than a 5000 psi gauge.

Perhaps someone knows of a reliable source of big-dial gauges.. I for one have always been jealous of the size of Andrew's...... gauge.

libbybapa · Post by **libbybapa** » Wed Jan 16, 2008 8:27 pm

I got it on eBay. In the time I was looking, nice gauges came up fairly frequently and often were not extreme in cost. IIRC I paid about $60 shipped for the one I have. Very nice to have the added resolution. I have seen advertised one of similar diameter and 3000 psi that had a small dial for a total of 3 revolutions and so a 1 psi increment. Often they are called "test gauges".

Andrew

Post by **Fatmobile** » Thu Jan 17, 2008 1:12 am

The 5 ton bottle jack I'm going to use has a hex top that I put a monkey wrench on and with it in a vice and a fat hammer in my hand I got it to turn.
The top was screwed to the center pipe, AKA the ram tube.
It came off seperately. and the tube remained stuck to the base.
The screw-on top held the outer shell to the base, when it was removed a little tap and the shell fell off.
I opened it over an oil drain pan.
It's the first time I've taken a bottle jack apart too.

libbybapa · Post by **libbybapa** » Thu Jan 17, 2008 1:26 am

I used "Automotive Goop" (available at Walmart) to glue the reservoir outer tube to the base on one and it worked fine and resisted diesel.

Andrew

Vincent Waldon · Post by **Vincent Waldon** » Thu Jan 17, 2008 1:33 am

The ubiquitous JB Weld worked well for this task, as well.