Posts

Posted on

Electrical Safety Tip

Confusing House wiring and Automotive wiring can get you killed.

My favorite hobby is working with cars and Jeeps. I have no trouble repairing or trouble shooting automotive electronic systems. I am also a licensed electrician working with residential and commercial wiring.

In AC wiring the standard is to use the white wire for the neutral which is commonly connected to ground. The green or bare wire is the ground. You can typically touch either of these safely. The black wire is the “Hot” wire having the supply voltage above ground. You defiantly don’t want to touch that one.

In car wiring, the battery voltage is normally the red wire. Often the ignition switched “hot” wire will be blue or purple. While 12 volts will not hurt to touch it, you want to make sure it does not touch ground or you will pop a fuse or maybe burn a wire.

The ground wire in an automotive circuit is coded black. Notice that this is the exact opposite of home or commercial AC wiring. If you are an automotive mechanic making repairs to your home wiring, you need to be aware of this critical difference. The black wire is the “HOT” wire in AC.

Also with home wiring, it is never safe to assume that the white wire is always grounded. In most lighting circuits, the hot is transmitted to and from the switch using a single piece of romex. This will have both a black and white wire in it. The white wire should have a black stripe or tag at the junction but it is very often missing.

Also, if the path to ground in the white wire is interrupted, the wire can be energized through the load. Never assume the white wire is safe. And always assume the black wire is hot.

Use extra caution when switching back and forth between automotive and house wiring so that you do not confuse the two very different color coding systems.

Posted on

Learning to make brake lines

Learning to make brake lines

I am getting a chance to learn a new auto repair skill with my current project. The Jeep I am working on is being converted from ABS to standard brakes. The front brake lines are very different in shape while the rear line just has a different fitting on the end.

I began by removing all the brake lines from the Jeep. The line to the drives side wheel was stuck in the connector to the rubber line. The nut rounded off inside my line breaking wrench. I removed the rubber line from the caliper and soaked the joint in PB blaster for a while. I then put the line in the vise and used a pair of vise grips to get it out. The nut was destroyed, but the rubber line was saved.

At the rear the hard line was also stuck at the joint to the rubber line. I used a torch to heat the joint. This allowed the flare nut to unscrew but the rubber line was damaged in the process. I bought a new one to replace it.

I bought a flaring tool at O Reilly’s and a roll of tubing and a pack of fittings from Autozone. I made a few practice flares on some scrap used line and on some of the new line before proceeding to the real lines. I should have just ordered from Advance Auto and got it all in one place.

The hard line to the rear was the right shape but had the wrong fitting at the end where it will attach to the master cylinder. The line to the ABS has a joint and coupling at the point where the non abs goes into the proportioning valve. I removed the joint and then put the correct fitting on the end of the line.

To put on the correct fitting, I first cut off the flare from the tube. I finally found out what the groove in my tubing cutter is for. It was able to cut right up against the flare and not lose much line. I then slipped on the correct fitting that I removed from a donor Jeep. I then used the flare tool to make the proper double flare for the line.

Next I began fabricating a new line for the driver’s side wheel. The line from the donor jeep was broken but gave me an idea of the correct shape. I cut a length of line and flared one end. I then slipped on two new fittings and flared the other end. I then used the bending tool to make a couple of bends. I will make the final shape once the master cylinder is bolted in place.

The last remaining line is the long crooked one that goes across the firewall to the passenger side. I have two choices on this one. The line to the ABS is longer and has the right shape most of the way. I may be able to cut it and reshape it. Then, I can install the correct fitting on the end. The other option is to make a whole new line from the coil of tubing I bought.

Update: Jennifer finished up the last line this evening. She elected to modify the original ABS line by re bending it and cutting it to the correct length. Put the fitting from the donor Jeep on the end to finish it off. Our Pro Tools flaring tool is working great.

[phpbay]brake flare tool, 10[/phpbay]

Posted on

Power Steering pump pulley removal and installation

Power Steering pump pulley removal and installation

When replacing a power steering pump on a Jeep Cherokee, you will have to remove and replace the pulley. If you buy a new or rebuilt pump, it will not come with a pulley nad you will have to reuse the original. Also, there are three bolts on the bracket that are very hard to remove with the pulley in place.

Begin by securing the pump in a vise. You will need a special tool to remove the pulley. The pulley has a removal flange made into the pulley and you will need a tool that hooks into this flange. If you get the new pump at advance auto, they will loan you the tool or you can buy your own so you always have it handy.

The tool had two clamshell halves that fit over the pulling adapter and the flange on the pulley. Slip the sleeve over the two halves to hold them in place. Put the pin in the center of the puller bolt. Turn the bolt to extract the pulley from the shaft.

The new pump will likely come with a bolt to press the pulley back on but the one from the pulley tool kit works much better. Choose the right threaded adapter and screw it into the center of the pulley shaft. Sit the bearing on top of the pulley. Thread the center screw onto the adapter through the bearing. Thread the press adapter onto the center bolt and tighten it to press the pulley into place. Once the pulley is on, remove the threaded adapter from the center of the shaft.

Posted on

Jeep engine bay fire

Jeep engine bay fire

Rebuilding Mr. Green Jeep

A few weeks ago I got a call that my friend’s Jeep had burned. We think it might have been caused by a power steering hose leak but no one is sure since there was so much damage under the hood.

Her insurance company declared it a total loss and gave her a check for the blue book value minus the scarp value. However she wants her Jeep back.

I have a parts Jeep similar vintage so I have been working to swap parts. However a lot of things have to be bought new.

The whole engine bay wiring harness is being replaced with the one from the donor Jeep. The big difference between the two is that Mr. Green Jeep had ABS and the donor does not. This makes the part of the harness that goes through the firewall on the driver’s side quite a bit different.

We elected to pull the whole harness and intake manifold as a unit rather than trying to disconnect all six injectors. This allowed us to swap the throttle body and all the other burned sensors in one unit.

The owner elected to buy a new brake booster and master cylinder. She also got a new radiator, and power steering pump.

The sticking point right now is the brake lines. The donor Jeep did not have front brake lines. The lines from Mr. Green Jeep are not the right shape for non ABS and they are also damaged from the heat of the fire. I have decided to bend all new brake lines to make sure there will not be trouble with the braking system.

The brake lines are holding up the restoration at this point as the intake such are in the way of getting to the brake lines so they need to be completed before I can move on.

When I went to remove the old brake lines, one of the front wheel lines was seized in the rubber brake hose. I hope I can get it out with heat but I may have to replace the rubber line as well. At the rear, the metal line was seized into the rubber fitting. I had to heat the fitting to get it out. The heat required caused the rubber line to break so that will have to be replaced as well.

I was able to recover the pulley off her melted power steering pump to install on the new pump. I was surprised that the new pump also did not come with a new cap for the reservoir. Luckily, Jennifer’s brother had sent her one from his parts Jeep.