diln911 Posted March 24, 2015 Share Posted March 24, 2015 Hey Guys (and Gals),I have a 1984 CF Heavy Rescue that I have purchased and have a lot of family history with. My goal is to preserve it back to the way it was when I was a kid and knew the truck. I have a couple of questions for you all. When I bought the truck, it had been sitting for about 2 years. The previous owner had run it out of fuel and it stayed where it was until I bought it. We put fuel in it, and primed everything up. The truck started, but it started wide open. It has an American Bosch pump on it. I spoke with my local Bosch dealer here in Richmond and they guided me through the process of trying to unstick the fuel rack which I never could do, so I had it towed. The Bosch dealer got the fuel rack unstuck for me and got the truck running. The problem was that the truck seemed to "hunt" for an idle somewhere between 600 and 1000 RPM. This would go on until I idled the truck up to about 900 RPM, and then it would level out and idle correctly without hunting, but the idle was set too high. When I would idle it back down to the desired 600 or so RPM, the motor immediately started the hunting up and down thing again. I was told by a number of folks that the governor on the pump is bad, and as such needed to be rebuilt. I planned on pulling it off, but on a totally separate issue one day I was lubing up the accelerator pedal because it was sticking. It has a Williams air control pedal on it and when you push it down it does not come back up on its own power, and you physically have to pull the pedal back with the heel of your foot. I sprayed some PB blaster in the there and worked the pedal back and forth to try and free it up, and to some degree it worked. I didn't think anything else about it, but the next time I started the truck it ran perfect at idle. No hunting or moving up and down in RPM ranges, and everything seemed to be fine. My question is this: Is it possible that the air controller on the throttle or even the slave unit in the engine compartment could be causing the up and down seeking issue I am dealing with. I do think the valve just below the accelerator pedal is leaking some air as well. I have driven a number of these in my life and I remember the pedals immediately snapping back when you let your foot off of them, so I know something is suspect. Do you guys suspect this might be causing the engine issue and not the injection pump. I hate to pull that pump off. Can you rebuild the accelerator assembly or should I just replace it? Any thoughts would be appreciated. It seems odd that the seeking condition stopped after I worked that pedal over. Thanks so much for any feedback. Its the EMC6-285 motor. Injection pump is APE6BB11OT6980D1. The truck runs great on the road and at speed. Quote Link to comment https://www.bigmacktrucks.com/topic/39390-cf-mack-fire-truck-restoration-injection-pump-question/ Share on other sites More sharing options...
hatcity Posted March 24, 2015 Share Posted March 24, 2015 the PB was able to work its way down thru the throttle pedal.If the whole thing is working fine now, just throw a bit of PB every so often.dirt, grime, "stuff" can get caught in there and bind it up Quote Success is only a stones throw away.................................................................for a Palestinian Link to comment https://www.bigmacktrucks.com/topic/39390-cf-mack-fire-truck-restoration-injection-pump-question/#findComment-283868 Share on other sites More sharing options...
gearhead204 Posted March 24, 2015 Share Posted March 24, 2015 diln911: as Hatcity said the blaster is probably doing its job. the way to find out if the throttle was causing the issue is to unpin the slave rod and then control the throttle lever by hand,if no problem it most likely was the air throttle. The air throttle should not be hard to disasemble and clean, most likely the steel piviot pin and the aluminum hsg. are having issues look for a roll pin that holds the steel pin in place, drive the roll pin out then the piviot pin clean lube and reassemble. Also check the slug that the peddal pushes on to make sure its free and clean. the terex scrapers i worked around had these throttles and this was part of my standard spring maintance to clean them up. Quote Link to comment https://www.bigmacktrucks.com/topic/39390-cf-mack-fire-truck-restoration-injection-pump-question/#findComment-283870 Share on other sites More sharing options...
diln911 Posted March 25, 2015 Author Share Posted March 25, 2015 Ok, that makes sense. The slave assembly in the engine compartment seems to be working properly and is very responsive to pedal movement. I'll disconnect the slave from the linkage and see what happens. Maybe it's a little combination of both. Quote Link to comment https://www.bigmacktrucks.com/topic/39390-cf-mack-fire-truck-restoration-injection-pump-question/#findComment-283934 Share on other sites More sharing options...
1958 F.W.D. Posted March 25, 2015 Share Posted March 25, 2015 I concur with the two previous knuckleheads my esteemed colleagues. I have driven several pieces of apparatus that had factory Williams air throttles and one that I know of that was converted to a Williams air throttle. You did have to lube them every once in a while with a liquid based lube (I seem to remember we used liquid silicone) so that it would penetrate all the way down the rod. (this is where gearhead gets excited because I used the words "lube" and "rod" in the same sentence.) I do believe that this was/is your issue. American Bosch injection pumps rarely had sticking rack or sticking governor issues (it happened, but was rare mind you.....) the Robert Bosch pumps on the other hand were a different story. Quote TWO STROKES ARE FOR GARDEN TOOLS Link to comment https://www.bigmacktrucks.com/topic/39390-cf-mack-fire-truck-restoration-injection-pump-question/#findComment-283941 Share on other sites More sharing options...
fxfymn Posted March 25, 2015 Share Posted March 25, 2015 Congrats on finding the rig. Ex-Chesterfield, VA??If you are not a member you should consider joining Old Dominion Historical Fire Society, the VA chapter of SPAAMFAA. http://odhfs.org/ Quote Money, sex, and fire; everybody thinks everyone else is getting more than they are! Link to comment https://www.bigmacktrucks.com/topic/39390-cf-mack-fire-truck-restoration-injection-pump-question/#findComment-284001 Share on other sites More sharing options...
diln911 Posted March 29, 2015 Author Share Posted March 29, 2015 Hey fxfymn,Yes, Ex Chesterfield walk in rescue. Company 4 Bon Air, Unit 49. The original was a cab over ford with this Young walk in. They swapped out the chassis in 84 with the CF. Truck stayed at company 4 until we bought the Salisbury Mack which was the new 49 and was tragically crashed. This unit went to station 14 and became 149 for a number of years before it was replaced. It went to a volunteer department in the Charlottesville valley area and then when they got rid of it, it changed hands a couple of times before I got it. I am familiar with the ODHFS. I don't have a lot of plans to do anything with it other than return it to its original state with a few suspension modifications and look at it in my garage. Quote Link to comment https://www.bigmacktrucks.com/topic/39390-cf-mack-fire-truck-restoration-injection-pump-question/#findComment-284487 Share on other sites More sharing options...
fxfymn Posted March 29, 2015 Share Posted March 29, 2015 I am almost positive that the CF chassis is one of the last produced by Mack. You should check with the museum to find out where it fits on the production list. Glad to hear that it didn't get turned into a service truck as the previous owner planned. Quote Money, sex, and fire; everybody thinks everyone else is getting more than they are! Link to comment https://www.bigmacktrucks.com/topic/39390-cf-mack-fire-truck-restoration-injection-pump-question/#findComment-284540 Share on other sites More sharing options...
diln911 Posted March 29, 2015 Author Share Posted March 29, 2015 Yeah it went through a bunch of uncertainty before I finally got it. I tried to buy it from the volunteer department that had it in the valley and was told my bid was not accepted because I was a career firefighter. Instead of selling it to me for a grand they sold it to a scrapper for less. Then the scrapper thought it was too nice to part out, and sold it to guy who was going to use it as a service truck. He decided it was too nice for that, and he is who I got it from. He left it outside for almost two years which has created a variety of challenges for me, but it's all there and everything works. I've managed to save the paint with a buffer and a lot of compound and elbow grease. I thought the last of production CF's came out in the 90's. The replacement to this truck and the sister enclosed cab CF pumped at 11, 3, and 5 were all Grumman bodies but early 90's Mack chassis? Quote Link to comment https://www.bigmacktrucks.com/topic/39390-cf-mack-fire-truck-restoration-injection-pump-question/#findComment-284547 Share on other sites More sharing options...
diln911 Posted March 29, 2015 Author Share Posted March 29, 2015 The 72 that I learned to pump on is on ODHFS, it's in Augusta county and I'd love to have it too, but the guy wants too much money for it and would not consider negotiating, so I had to walk away. Can't save them all I guess. It was unit 44, previously 113. I've got a bunch of pics of them. Quote Link to comment https://www.bigmacktrucks.com/topic/39390-cf-mack-fire-truck-restoration-injection-pump-question/#findComment-284548 Share on other sites More sharing options...
gearhead204 Posted March 29, 2015 Share Posted March 29, 2015 I concur with the two previous knuckleheads my esteemed colleagues. I have driven several pieces of apparatus that had factory Williams air throttles and one that I know of that was converted to a Williams air throttle. You did have to lube them every once in a while with a liquid based lube (I seem to remember we used liquid silicone) so that it would penetrate all the way down the rod. (this is where gearhead gets excited because I used the words "lube" and "rod" in the same sentence.) I do believe that this was/is your issue. American Bosch injection pumps rarely had sticking rack or sticking governor issues (it happened, but was rare mind you.....) the Robert Bosch pumps on the other hand were a different story. [ HEY, HEY, HEY Yardo that was uncalled for, now "lube hole" would be a diffrent story. But oil on a rod just reminds me of a "dip stick" 1 Quote Link to comment https://www.bigmacktrucks.com/topic/39390-cf-mack-fire-truck-restoration-injection-pump-question/#findComment-284651 Share on other sites More sharing options...
fxfymn Posted March 30, 2015 Share Posted March 30, 2015 The reason the rigs were built by Grumman was that Mack had already ceased fire truck production. Chesterfield was big on Macks, so they bought several chassis that were finished by Grumman.The "scrapper" that had your truck is actually a collector and member of ODHFS and makes an occasional visit to this site. Very nice guy who will help you out if you need it. He does scrap out any rig that is beyond help, but if it is savable he tends to move it on. Quote Money, sex, and fire; everybody thinks everyone else is getting more than they are! Link to comment https://www.bigmacktrucks.com/topic/39390-cf-mack-fire-truck-restoration-injection-pump-question/#findComment-284708 Share on other sites More sharing options...
diln911 Posted March 30, 2015 Author Share Posted March 30, 2015 Well... I was glad he didn't scrap it. Thanks for everyone's help. Quote Link to comment https://www.bigmacktrucks.com/topic/39390-cf-mack-fire-truck-restoration-injection-pump-question/#findComment-284729 Share on other sites More sharing options...
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