This not so much an article on diagnosing a no start problem…as much as it is a study in one mistake snowballing into more..and resulting in a no start problem.
Here is how it all happened. I drive a pickup truck equipped with a straight drive transmission. This particular vehicle uses a hydraulic clutch release system. Anyone who has operated a vehicle with an old style bell crank system can tell you that they are cumbersome, hard to use and unreliable. So a hydraulic system is a wonderful alternative. It is smooth, reliable and greatly reduces the effort to dis-engage the clutch.
Please keep in mind, my truck has over 200 k on it..so a failure like this is not a surprise. Now I had noticed one day that my clutch pedal was feeling low…too much travel before taking the clutch in. A look under the hood revealed that the clutch master cylinder was empty of fluid. I refilled it with brake fluid and went on my way. Two days later I again noticed that the fluid was low and topped it off once again. But I also noticed that there was no fluid leaking out from underneath the vehicle. This thing is now using a pint every two days..with a drinking habit that bad one should be able to notice a puddle I thought. But, i couldn’t find one. A clutch master cylinder is mounted on the firewall, so the only other place the fluid had a way of escaping..was inside the cab. A look under the dash revealed a wet and brake fluid soaked carpet. Time for a fix !
A stop at a parts store and 57 bucks later I had a replacement master cylinder. It was just a matter of yanking off the fluid line, removing two bolts and the old master cylinder was in my hands. I put on the new one and topped off the reservoir and..hoping all was well..operated the clutch pedal. It went to the floor with no resistance at all. Air in the line. I crawled underneath and opened the bleeder valve on the slave cylinder and watched as it did not attempt to gravity bleed. This was bad. Not giving up hope..I uncovered my trusty hand operated vacuum pump..attached it to the bleeder valve and began pumping. And before too long..I had fluid flow. This is good. I let it go awhile and after closing the bleeder valve tried the clutch again. Still nothing.
Next I enlisted another person to pump the pedal for me while I operated the bleed valve. Got lots of air, some fluid…and it still didn’t want to work. It was time for some research. So I go to the web and look at anything I can find relating to a hydraulic clutch. Some said gravity bleed worked for them. Some said the vacuum pump was the way to go. Others advocated both methods and a second person to pump the pedal. One thing was becoming clear..this was a common problem..and there didn’t seem to be any one answer to it. Until..I ran across a wonderfully logical article that showed me a way to do this with little muss or fuss. It is called reverse fluid injection.
All you need is an oil can that has the trigger for squirting the oil..a length of clear plastic tubing..and a wrench. Here is what you do, you open the bleeder and drain out the fluid. You attach the tubing to the bleeder, or in my case, I pulled off the line to the slave cylinder, and attached the hose to it. You attach the other end of the tubing to the spout of your now brake fluid filled oil can..and start squirting. So easy…as the fluid goes in..the rising fluid level pushed the air in the line…out ! Just keep an eye on the master cylinder so it doesn’t overflow. Once the reservoir has fluid in it..you can top it off from under the hood. Back under again, you put your line back on, pop open the bleeder on the slave cylinder…when the fluid flows out..close the valve and tighten..top off the reservoir and…you are finished.
And all of THAT, led me to a no start problem. No crank, no start. Most straight drive vehicles have a clutch safety switch. If the clutch isn’t “in” it will not start. Apparently, the brake fluid coming through the fire wall seeped into this switch..and disabled it. Maybe brake fluid has some insulating qualities? I dunno. This safety switch was the first thing to enter my mind as I pondered this no crank problem. So under the dash again I feel around near the clutch pedal up near the top in an effort to find this finiggling switch. AH ! There it is ! A quick snip from a pair of cutters and I had the offending wires in my hand. I stripped the insulation from both..twisted the bare wire ends together..and, there I had it. One safety switch bypassed. And it still would not crank. I looked again at the wires and considered…surely a piece of wire the size of a pencil lead could not carry the 40 plus amps for a starter. Well, lets look around for anything else first I decided. This led me into looking at voltage levels at the battery. Then the heavy wires leading up to the ignition switch, the fusible links and to finally replacing the ignition switch itself. This had me removing a great deal of the dash panel and dropping the steering wheel for clearance. And still no start. Starting to get desperate I found an article that described adding a second solenoid relay that one could operate with a dash mounted switch. This would entirely bypass the built in crank circuit..thereby forcing the darn thing to turn over. So another trip to the parts store and I came back with a ford type relay, some length of wire, a stubby battery cable and some connectors. Under the truck I went and dropped the starter so I could begin this hair brained idea. I rewired the solenoid and starter connections..tied in the new relay, and after reconnecting the battery I was ready to try this jury rigged scheme out. I touched the wire to the hot post on the battery..and she cranked right over ! And kept right on cranking too! Wouldn’t quit ! I suppose it’s a good thing it still wouldn’t start.
Abandoning this whole plan I went back under, dropped the starter again and returned it to it’s original configuration. Which is when my brain kicked in again, and I realized I had passed a major clue. Those two really small wires that could not possibly carry the required current without becoming a carbon conversion in the process. Feeling very stupid I took another peek under the dash and discovered that the real clutch safety switch..was down near the floor..not up near the top. It just clicked out of it’s mounting and I wrapped a zip tie around it to hold it closed…and tried to crank the engine again. It worked. Turned over very well actually. But it did not start. Hmmmm…NOW what? I went and got the lawn mower gas can and dribbled a small amount into the throat of the throttle body injection and tried to start it again…and it fired right up. SO ! What does this tell us? Bad fuel pump? Clogged filter? And why is all this stuff stemming from just replacing the clutch master cylinder?
I removed the fuel line to the t.b.i and turned the key on. I am supposed to get a squirt of fuel here for three seconds to pressurize the system. I got nothing. A volt meter on the fuel pump relay revealed voltage for 3 seconds after turning on the key. So…bad pump? I am now contemplating dropping the tank and replacing the pump when I again recall those two wires I first cut. I take a look at them. Still tied together….but what if…I untied them…turned the key and nearly got a face full of gasoline as the removed fuel line spouted out strong jet in my direction. I quickly replace the fuel line to the t.b.i. and cranked the engine. It started. At long last, I had a working vehicle again.
You are no doubt wondering just what those two little wires were? It was the switch, controlling the cruise control. While under cruise…if you touch either the brake or the clutch…the cruise control will release. And apparently, by having the switch closed..cause I had cut, skinned and then rejoined the wires..the computer was fooled into thinking the cruise control was operating…and possibly, it also thought the engine was running and would not allow the fuel pump to pressurize the system. Thus…a bad clutch master cylinder led me on the wildest chase for a no crank no start problem I have ever encountered. To be fair..I made some misjudgments. Jumped to some conclusions. But, dumb luck and stupidity won out in the end.