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twin engine scraper throttle?

CAT D9H ยท 2009-03-12 00:51

Ok I have been around newer electronically controlled twin engine scrapers , and very few mechanically controlled scrapers (ie.627), My question is on the old mechanically controlled engines was there a throttle cable running from the pedal in the cab all the way through the neck , down the bowl to the rear engine ? I have never been exactly sure how that works , please let me know thanks guys

Replies17
  1. #1Cmark2009-03-12 03:06

    The throttle was air controlled. Valve under the pedal and small air-brake-style actuator on the engine. There wasn't a lot of feel with them. Pretty much either all or nothing.

  2. #2stumpjumper832009-03-12 06:49

    terex's ts14b had an air controlled rear engine. syncronized air shifter, air throttle, and manual start up, walk back and hit the button. Only bad thing was that if you had an air leak, it didnt move, air brakes too. I have a shifer come out of sequence on me once, front trans was a gear ahead of rear.... anyhow thats how they did it.

  3. #3Meangreen2009-03-12 11:51

    The older TS-14's 6UOT and 7UOT had a thorttle cable from front to rear. And to tell the truth, I liked that better than the air controls on later models.

  4. #4CAT D9H2009-03-12 15:49

    thanks guys , I wouldnt imagine there was any feel in the pedal

  5. #5surfer-joe2009-03-12 18:36

    TS14's were all air on back, at least those I ran. TS24's/TS32's were air on thottle, electric on shift. You could actually stick your finger into the shifter and manually toggle the rear tranny into reverse with the front trans still in forward. I used to do that just to mess with a pushcat hand sometimes. He'd have a fit when he saw the rear wheels turning backwards........ There isn't any "feel" with air thottles, but you can feather the thottle with experience and by just listening to the engine, oh, ummmmm, I forgot, todays operators can't hear squat because they got a walkman or something stuck in their ears. Anyway, I did it all the time, no problem.

  6. #6Turbo218352009-03-12 19:59

    Feather is right. I found if i just tap the rear throttle when i needed to slowly add power it worked nicely. It seemed it would take the air a few seconds to make the adjustment on the rear of the machine. Still love them 14s for moving dirt, big green ugly and loud, not much better than that.

  7. #7CAT D9H2009-03-12 20:47

    Tell me about it, a guy I used to work with would always have those damn earmuffs with a radio built in them , looked goofy , plus you couldnt imagine the things he tore up becaus he couldnt hear his ground man

  8. #8RDG2009-03-12 21:41

    When you are inside a cab its abit hard to hear the back engine but are able to see the flapper cap on the back motor on the 627B and have found this gives a bit of an indiction of what the other half is doing, when its half open you have about half throttle fully open is full power.Have had one of our 627s down with an air throttle valve problem, its worn out cant be repaired and a new one is $3000 and has to come from the USA.

  9. #9surfer-joe2009-03-12 21:51

    Can't find a good used one, eh? How about a good machine shop doing some build up and re-machine work? Might be cheaper, and faster than waiting for part from good ole USA. What the hey, maybe try for a good used take-off from a machine in a boneyard here, like in California. I'd bet any of the California dealers would have one for less than new, and some of the other non-dealer boneyards might have one too. For dealer boneyard try Quinn Machinery in Fresno. For other kind of boneyard try Modern Machinery in Missoula, Montana.

  10. #10zhkent2009-03-12 23:30

    Those are a weird valve on front. Had the one in my scraper apart and i'm still not sure how the darn thing works. I do know I couldn't get the valve to release the pressure correctly to let the back motor slow down. Robbed one off of parts scraper.

  11. #11Neil D2009-03-13 19:39

    627 air throttle I am working on one of my 627's with a similiar problem-but it ain't gonna take $3000 to fix ,most of the bits are a handfull of dollars, you must have high import taxes? Neil

  12. #12Shaunrh2009-03-14 07:35

    Price I am thinking for 3000 dollars someone has ordered the whole group and they are in for a shock when it turns up.I am very surprised that there is no parts here in the land of Oz for a 627 throttle. Shaun

  13. #13alan627b2009-03-15 00:14

    Cat has some kind of conversion kit to adapt the newer throttle assemblies to the older 627's. I believe they use one from an E or F model to accomplish this. The mechanics I am friends with told me they have done this to some of our 35-40 627B models. It requires a little cab floor alteration. The good news? A few hundred instead of a few thousand dollars. I could try and get you a PN if you want. Might take a little while... Alan627b

  14. #14Neil D2009-03-15 18:59

    Alan Can you get the p/n please? Thanks Neil

  15. #15alan627b2009-03-20 01:09

    Answer for Neil I asked one of the wrench twisters at our shop yesterday, and there isn't an actual kit available. They buy a throttle valve for the 627E/F application, do a little floor surgery to get it to fit. Considerably cheaper than one for a 627B ($1000 USD!) if you can get one, they can't even get service replacement kits for the valve any more. Get out the gas axe or the plasma cutter, Neil... Still no answer on the muffler brackets either, the fearless leader wasn't there to ask! Alan627b

  16. #16JD DURFEY2009-03-20 22:23

    I never minded the air throttle on the rear engine when I ran a 627. I am a bit of a "hack" and only use the rear engine when I could have it floored. I did not like the air throttle on a 623 F that I used to run. That was when I needed some precision, and it seemed like I could never quite get it right, either too much or to little. I think the 657s I ran had air throttles too, but once again I just kept it floored all the time.

  17. #17Hollywood627G2009-05-08 12:55

    lol, i got me a handy dandy little digital gauge on mine that lets me know the rear engine rpm. Gotta love technology