... as in the predominant color of those Harbor Freight ads, boxes, and their store. I recently needed a cylinder leak-down tester for my "fleet" of 7.3l blocks, and I thought I could get by on-the-cheap for this one little task. I was wrong. Here is the product I bought, Harbor Freight item 62595, along with parts I utilized in an atttempt to make it work:



After reading several reviews, experimenting for many hours, and modifying the tool to make sense - I have come to one inescapable conclusion: This thing is good only for using 10-15 PSI to look for leaks. The gauge on the left reads 0-100 PSI and the gauge on the right reads 0-10 or 0-15 PSI, but the face on the right-side gauge reads backwards in percent - with green yellow and red backgrounds. Even with a change of gauges, the orifice in the device is designed to do what it does at 0-15 PSI.

I rarely rail against a product, but I'm doing it now. Buying this tool to check for cylinder leak-down on a 7.3L means you will soon be buying a different unit to get the job done - plain and simple. My next unit is provided by OTC - I'll report on how that goes.

This has been a public service announcement of the Stink-N-Rich research and development team.

 

Good to know...may I never have to use one...

 

Tug, this seems more of a "Warning: Problems with Harbor Freight Cylinder Leak Down Tester" and less of a "Red Alert" kind of thread. It might get more exposure, spreading your experience better too.

Stewart

 

Wasn't sure what I was going to see when I opened the thread lol. Thanks for the heads up Tugly! I myself use SOME of their tools and usually don't have too many problems. This one I'll be sure to stay away from.

 

I fixed the title... a little.

I've been reluctant to approach this topic because it's so hard to describe the issues at play. I get plenty of great advice on how to operate the tool, how to perform the test, and how to find TDC in the cylinders, but unfortunately... much of the advice I received did not address the issue at hand. The only way I can demonstrate the complete and utter failure of the tool is to take a series of videos and break out the easel with charts and graphs. I'm in a crunch with my available time right now, and spending a big chunk of that on a full-blown demonstration just isn't feasible right now. If this was fall or winter, I could put on a good show for educational purposes.

Until that time, all I can do is convey that there is a large number of reviews on this tool, sharing the woes of exactly what I experienced. I looked at the glowing reviews of the OTC leak-down test tool, plus I have great results with the OTC compression test tool - so I may have something useful to report soon.

This whole leak-down test thing has been drummed into me for years, and I've been dreading it because I knew it would mean buying tools and equipment for this one task - plus it's time-consuming to rig the engine to not spin when you pressurize a cylinder with the valves closed if you don't nail TDC. I've been working on conducting a successful leak-down test with my little available time for months now, and I have reached critical mass. My hope is to feel better about the whole thing if I can string some caution tape around this particular bear trap. I've got some spare yellow tape lying around that can come in quite handy right about now.

Oh... and the temps are in the 100s this week. Not very conducive to a gleeful attitude.

 

Aww, you'll get the money back in Rental fees from us......

 

After many months of sifting through the forum and on-line/neighborhood stores to sneak up on a cylinder leak-down test, I finally netted that bass turd. It just takes the right tool.

The HB is a confirmed dud - I am forced to announce it must be avoided. I got good numbers from my OTC tool, then I repeated the same procedures with the Horrible Fright tool. The HF tool said I was making more pressure in the cylinder than the air supply, but even when reading the gauges in reverse - it didn't match my numbers from the very sensible readings I got on the OTC device. I'm now returning to my "I'll be Frank with you" thread to report there.

 

I took the HF tool apart - I wanted the hose fittings, gauges, and regulator for other projects. I looked in the rectangular base piece, expecting to find an orifice for a pressure differential with flow. Nope. The rectangular aluminum piece is nothing more than a wide-open manifold with a bunch of 1/8" NPT holes all over it. I'm talking Swiss here... as in cheese. This was never gunna work.

 

I really don't know why they put the Rubber Nipple Adaptors in the kits.


In order to be effective one must be able to move about the engine bay (any engine) to hear air movement. They may work on a small single cylinder engine where you can turn the crank by hand but can't imagine them for any other application.


The difference in reading is obtained by a diameter hole reduction to the second gauge. Thereby allowing for a (I think) 30% reduction. Which, is about as large a differentiation as one would want as 30% would be bad, very bad. But, manufacturers vary with their testing variances.


If its hooked up and charged with air with the valve open, it just skewed the gauges accuracy and might as well be a paperweight there forward.


A single gauge can be used if you know the pressure being supplied to the gauge. ie: 90 PSIG. A drop od 9 SPIG would indicate 10%, 14 would be 15% and 18 would be 20%


All in all, they are a good diagnostic tool. But, seldom used by the trained mechanic. Why? I don't know. I use mine often.


The neat thing about a leakage test (as opposed to a compression test) is that it's faster and easier to figure out where the pressure is going. If you hear air coming out of the tailpipe, it indicates a leaky exhaust valve. Air coming out of the throttle body or carburetor would point to a leaky intake valve. Air coming out of the breather vent or PCV valve fitting would tell you the rings and/or cylinders are worn.


A cylinder that has poor compression but minimal leakage usually has a valve train problem such as a worn cam lobe, broken valve spring, collapsed lifter, bent push rod, etc.


If all the cylinders have low compression but show minimal leakage, the most likely cause is incorrect valve timing. The timing belt or chain may be off a notch or two.

 

Over at WeldingWeb there are stickies for "Harbor Freight tools that suck" and "Harbor Freight tools that don"t suck" The whole forum is dedicated to Harbor Freight. Nothing like welders and machinists/fabricators giving their experiences with HF tools Harbor Freight

 

They don't - they provide spark plug adapters... totally useless on a diesel. I made the tool to adapt to the glow plug hole, and it has always been very reliable for me. Of course... I have to wear gloves when holding the nozzle in place, lest I gouge my palm.

I had a very close look at the HF tool, and I finally spotted what could loosely be referred to as an orifice. That thing is so huge, that if you ever got a readable pressure differential at 100 PSI - you're pretty much shopping for a new engine.

 

I used to own a Snap-On EEPV309 leak down tester that was loaned and never returned.....I would have sent it to you had that unfortunate event not occurred. Glad the OTC version is working for you. They do make pretty decent stuff, not Snap-On nice though :-)

 

...or Snap-On expensive. Snap-On $300, OTC $70.

 

Definitely. If I buy another leakdown tester it will be the OTC or possibly a used Snap On if it's in the $125 range. The Snap On are very polished and the adapters for them are very nice. Nothing wrong with OTC, I've used them and they read well.

The good news is "Frank" reads quite healthy and you can proceed with dressing him up for Stinky.

 

Well Tugly, felt your pain a number of years ago. I shop and buy HF for cheap shop tools I don't use often, hand tools to beat and pry on, and expendables shop items. But I learned as you have confirmed not to by any critical tools for measurements, testing, torquing, etc from HF.

I've searched but not found where you posted your results or elsewhere someone posted what expected cylinder leak test results should be. Specifically for a cold diesel. Most all test procedures state engine warmed to operating temp. I did a compression check and was about to pull the heads. Then had several suggest that I do a leak down test to check the bottom end before pulling the heads. I was just going to rebuild the top end. But thinking was if I found something on the leak down test may want to pull the entire engine and rebuild or replace. Or put back together and sell as is

But about your readings from the cylinder leak down tester..here is where I'm at:

Compression test (cold) showed"
1-385
2-390
3-385
4-390
5-390
6-400
7-420
8-400
Thinking I may have went an extra revolution on #7-9.

Also, performed a cylinder contribution test on 30 mile trip for parts and back and it checked good. Once it got up to operating temps and I made a stop or two, #3 and #8 would show blips on the chart but would go away once I started driving.

I've pulled all injectors and glow plugs. Evacuated all cylinders. Started in firing order with #1 and #2 polished cups, re-installed injector on the cylinder being tested, and cleaned glow plug hole/base, set TDC, backed off rocker arm bolts to insure valves closed (or should be). Read on one source to set tester pressure at 40 PSI. But I got me the OTC tester too and it showed lowest on it's chart 75 PSI. So went with that.

I got 36 PSI on #1 and 57 PSI on #2. Which is off the chart! So this is were I stopped. I've been reading and researching on what I may be doing wrong. Surely this can't be correct. I wouldn't think so with decent compression numbers. I hope not.

All the air, or the only place I can hear air coming from is in the crank case and dip stick. I've drained the oil, and coolant, and radiator already as was about to pull the heads. Also the oil cooler to pressure check. I had the intake off on the #2 side, checked there close to valve, intake on other side, upper end of up-pipes, water pump and heater hose connection, basically anywhere I could with a section of plastic hose and I could only hear air when pushing it down by the push rod, oil dipstick, and at oil cooler location.

Is it just not a possible to cylinder leak check a cold diesel? Or I'm I just missing something?

If it's not obvious, my baby since 02, is in the ECU unit of my shop on life support! I'm in the process of trying figure out which direction to go with her.

Blue