| Author | Message | ||
     Geoff Wootton Grand Master Username: dounraey Post Number: 601 Registered: 5-2012 |
There are many times when it is useful to be able to touch the HT leads when the engine is running. Turning the Distributor when timing or removing a plug cap to detect a missing cylinder are two examples. The problem for me is many years ago I took a 20 second blast of 20Kvolts up my arm from a leaking HT lead. I was unable to release the lead as my hand muscles had contracted onto it. I was "saved" when the friend I was working with turned off the ignition. This is not something I wish to repeat, not least because of the humiliation of seeing my friend falling about laughing at my ordeal. Since then I have never touched HT leads with the engine running, which is inconvenient. I have done a trawl of the web but cannot see any gloves marketed specifically for the purpose of insulating you from HT leads. I was wondering how other members of this forum deal with this problem and how many just take the chance. Geoff | ||
| Bob UK Unregistered guest Posted From: 94.197.122.90 |
Special insulated plastic pliers, these are made especially for taking plug leads off a running engine. Electric shocks are not so severe if your hand or arm is earthed to the engine, because the path is only as far as where your arm is earthed. If you are not earthed then it goes all the way to your feet. I before starting the engine make sure that the plug caps or dizzy end can be easily pulled off, if not a bit of petroleum jelly helps. If you turn off the workshop lighting any HT leaks can be seen. I had a car in that had a misfire and in the dark I could see a tiny blue haze around the coil pack. I gave it a WD40 dose and the haze went along with the misfire. So I fitted a coil pack. The pack was £275 Saab. Which is why the testing had to be certain. The fault codes said misfire events no2. I am glad that my car coil is less than £30. Note HT shocks are dangerous and can cause the heart to short pump and can be fatal. This happens because one hand is propping up the mechanic because he's old and has a bad back. While the other hand is poking the plug caps around, and the HT goes across the chest. My sparks guy has gloves for working on live mains. These are rated to 500v and are 1/4 thick rubber. So 20kv would be very much thicker. (Message approved by david_gore) | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 923 Registered: 9-2004 |
Geoff, Gloves can be bought, these are for the testing and working on electric cars. I'm on my second Leaf the torque is mind blowing,on par with my porsche!! Spraying WD40 oil on any electrical items is a no go for normal use as the electrical fields collect dust etc that stick to the units causeing arking, just what you do not want. | ||
| Bill Coburn Moderator Username: bill_coburn Post Number: 1558 Registered: 4-2003 |
In my school holidays I used to work at a local garage sweeping the floors, scraping carbon off components and asking a million questions. Since the second world war was barely over and there were no new cars, veterans of the thirties started to appear, severely limited by petrol rationing. One of the apprentices used to demonstrate on side valve cars how he could stop an engine by simply spreading his large hands across the spark plugs. We little wankers watched agog. One day he didn't stand again! Fortunately I wasn't there for the demonstration. I was there however one afternoon when another apprentice was working on the front suspension of one of the first Holden cars. For reasons I cannot remember, he undid the upper outer wishbone joint without supporting the lower wishbone. The last few threads of the swivel eventually gave way, the lower wishbone slammed to the floor and the coil spring escaped. Its trajectory from the suspension to the wall opposite coincided with the lad's head at just about eyebrow level. We all heard the bang and rushed over to the most gruesome sight I can remember. It was my first experience of profound shock where my eyes simply could not convince my brain what I was seeing on the floor, other cars, the wall and the under-roof space. My stomach simply divested itself of my breakfast as did those of other witnesses. Afterwards we realised that none of us realised we had none this, apparently it being entirely reflexive. The garage was closed for a week while they cleaned the place up and let the 'staff' recover. Shortly after I had to return to school somewhat wiser! | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 602 Registered: 5-2012 |
Bob, Patrick, Bill - Many thanks for your replies. I think I'll play safe and stick to my normal procedure i.e. moving the distributor with the engine off, particularly after the warnings regarding the danger of receiving these high voltage shocks (40Kvolt with my new coil). On cars I've had in the past it was possible to grasp and move the distributor by the casing, well below the HT leads and cap however as you will know, on the SY1 it is impossible to do this without brushing against the HT leads. I will check check out the plastic plug pliers next time I'm at the auto shop. They would be a useful addition to my tool kit. Regards Geoff | ||
| Bob UK Unregistered guest Posted From: 94.197.122.83 |
Wipe the WD40 off after. I use it as a cleaner. Do not spray on running engines because the propellant is butane. Thought I had better explian that before someone does. I have lead a charmed life on the gorey stuff, the accidents seemed to happen while I am not there. I saw a hole is an asbestos roof where a large spring escaped, it was quite round. I saw an apprentice try to use a big 1" drive impact gun on a large nut on a cconcrete truck. The rules were hang the gun on the balance chain then two to hold the handles. He man handled the gun on and pressed the trigger on max and the gun threw him to the floor. He sprained both wrists. He was warned about doing it just a week before. A lad at Stratstones Jaguar used to sick a screw driver up a plug cap and make sparks come from his nose to the edge of the bonnet. If he was standing next to a running car one kept away because he would touch you and you would get a shock. I went to buy a second hand magneto for a BSA and to test them I used to flick the armature round with my finger in the HT brush hole to check for HT. A mate who didn't know anything about mags or ignition tried it and he was most shocked. I sort think that us motor mechanics seem to develop an ability to absorb the shock better than others. Probably totally untrue. I am pedantic about safety. Working on cars is hazardous, not dangerous if one knows the hazards. So many people just blindly carry on. They don't read safety info on products for instance. They support cars on jacks only. They trip over stuff on the floor. The very big forgotten danger with mechanics is lower back problems. I have this and it now limits me. Which is why I advocate doing stuff slowly and tomorrow's another day. However because I have to sit down to rest I tend to take a bit off, say a stat elbow and sit there cleaning it and then maybe file out casting marks and polish it. Then start on the bolts. So I do a nicer job( not better just nicer). It doesn't hurt to read the boring safety stuff and it's guaranteed that those who don't read it will be surprised at what they didn't know. It all looks so obvious until you check. When I was fighting fit I could do a clutch in 30 mins on a cortina, I had to wear gloves to take the cover off because it would still be hot. I took an engine out of a minor in 20 mins. Spanner in each hand and screw driver in my teeth and a gear box on my head, all in a day's work. It paid for my house deposit. One mechanic manage to fit a new SU fuel pump with out turning the engine off. I tried it but run out petrol before I could get the suction side connected. Another game was to change a fan belt with the engine running. (Message approved by david_gore) |
