Using regulator repair knowledge to fix my truck!

[Eric Sedletzky]

A while back @rsingler posted an article about the importance of meticulously repairing a reg that had IP problems and also O-ring related sealing problems.
My older Toyota Tacoma pickup that now has over 300k miles on it began developing evaporative emission problems, constantly causing the check engine light to go off and throwing an 0440 code (evap leak). Most of the time this is always a faulty gas cap. California compliant cars since the 90’s all have to have sealed gas tanks where no fumes can escape. Any fumes go into the intake manifold via a hose so fumes get burned up. If the computer senses a leak anywhere other than the evap hose it will set off the check engine light.
So I checked the gas cap and sure enough the sealing O-ring was cracked and worn. So I sourced another giant and thick O-ring that was about the right size and it worked…for a while.
Then the check engine light started going off again. Good thing I have my own diagnostic unit!

So I took off the gas cap and looked at everything very carefully. What I noticed was at the bottom edge of the gas filler pipe there were some deep scratches from the gas pump nozzle dragging across it for the last 20 years. So I took some 220 sand paper and sanded out the deep scratches then went up in grits finer until I ended up at 2000 grit. Probably overkill for a car fix but never the less the land where the O-ring sits is now flawless!
Next I checked the land on the gas cap itself and it was dirty but looked fine. So I cleaned it up.
I put a little silicone on the O-ring (which I looked over carefully too) and reinstalled it, tightened down the gas cap and cleared the code.
So far it’s held and after three tanks of gas, the check engine light has not gone off, so I guess I fixed it!

Thanks to @rsingler and his knowledge, it got me to think about how important O-rings are and especially the lands they rest on.

 

[-JD-]

Should have used Christolube or Tribolube instead of silicone, You wouldn't want anything potentially flammable in such a sensitive location.

 

[Kupu]

Gaining regulator repair knowledge was key to fixing pressure issues on a sprayer I sometimes need to use for work. The pressure was often annoyingly low, the fix according to factory repair techs was to replace wear parts as needed. So I frequently rebuilt the pump over the years, but it never regained the crisp factory fresh high pressure.

After learning about adjusting piston regulator IP with shims, it dawned on me that it might be possible to permanently increase the sprayer pressure by adding shims to the spring of the pump. A pressure gauge was also rigged up and attached to the high pressure area of the pump, to measure the change and ensure my hotrodding did not dangerously increase pressure beyond the rating of the unit.

The result was a better than new sprayer without the need for frequent parts replacement. Satisfaction.

 

[lowwall]

There's a pattern here. I used what I learned in the class to fix the fancy (i.e. overpriced) designer faucet in my kitchen sink.

Since then I've done several minor plumbing repairs. It's all just chromed brass and o-rings after all.

 

[lexvil]

It’s all fluid power, I started with hydraulic systems on nuke subs, refrigeration, HP boilers, scuba gear it’s all the same principle just different pressures and temperatures.

 

[Jeff_O]

It’s all fluid power, I started with hydraulic systems on nuke subs, refrigeration, HP boilers, scuba gear it’s all the same principle just different pressures and temperatures.

I had my fairly new Food Saver Vacuum Sealer suck up liquid smoked salmon salt brown sugar water into the unit. Draining more moisture from the cooked fish made on a charcoal water smoker could have helped. Also hang the seal bag over counter edge. Gravity would let air out but not denser liquid as much. Still better used rigid vacuum container with vacuum lid. Well took apart the reed valve pump and gasket/reed valve, and needed to get replacement part. It just was not cleaning up. Authorized repair shop was leading me to believe I could get the part, but when there they said let's look at it. They would not sell the part. Took a few days of soaking and light scrubbing in soapy warm water and I have it still 30 years later, does that suck?

 

[lowwall]

I had my fairly new Food Saver Vacuum Sealer ... took a few days of soaking and light scrubbing in soapy warm water and I have it still 30 years later, does that suck?

Guess it does suck

I did find the limits to my service tech aspirations with my superautomatic espresso maker. It quit working one morning. I found the service manual online, went through the diagnostics and determined the vacuum pump had failed. It was possible to order the part, but replacement required removing and then replacing a bunch of soldered electrical connections so I threw in the towel and took it to a tech.

Who is the @rsingler of small electrical stuff? I think I just need to add multimeters and soldering knowledge to complete my Master Home Handyman cert

 

[BoundForElsewhere]

Gaining regulator repair knowledge was key to fixing pressure issues on a sprayer I sometimes need to use for work. The pressure was often annoyingly low, the fix according to factory repair techs was to replace wear parts as needed. So I frequently rebuilt the pump over the years, but it never regained the crisp factory fresh high pressure.

After learning about adjusting piston regulator IP with shims, it dawned on me that it might be possible to permanently increase the sprayer pressure by adding shims to the spring of the pump. A pressure gauge was also rigged up and attached to the high pressure area of the pump, to measure the change and ensure my hotrodding did not dangerously increase pressure beyond the rating of the unit.

The result was a better than new sprayer without the need for frequent parts replacement. Satisfaction.

I'd like to see the video of you cleaning your driveway, deck or murder room with a hotrodded pressure washer.

 

[Gene]

Good job on playing automotive detective with your Toyota.
I have a Land Rover that's quickly approaching 300k miles and the check engine light is almost always on. I'll check for some deep scratches on the gas tank filler neck. Hadn't thought of doing that before.

 

[Bob DBF]

Guess it does suck

I did find the limits to my service tech aspirations with my superautomatic espresso maker. It quit working one morning. I found the service manual online, went through the diagnostics and determined the vacuum pump had failed. It was possible to order the part, but replacement required removing and then replacing a bunch of soldered electrical connections so I threw in the towel and took it to a tech.

Who is the @rsingler of small electrical stuff? I think I just need to add multimeters and soldering knowledge to complete my Master Home Handyman cert

I'm surprised you haven't run into electrical problems before this.