Hard Shift? Possible Vacuum Problem
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Hard Shift? Possible Vacuum Problem
This may have nothing to do with the problem shifting but. Yesterday I replaced my glow plugs. In doing so I cracked a injection fuel line. So its leaking. Got a replacement on the way. Truck is running like crap. Very rough idle. When it shifts feels like im getting hit in the chest. I have to let up on the throttle for it to shift otherwise it just keeps reving. Can this be caused by one injector line leaking? Would the glow plugs affect shifting. Also why does my truck feel like its got more acceleration now as well.
I was reading this post and its exactly they way it feels for mine.
Also will fixing the vacuum pump fix my stiff brake pedal as well.
2 birds with one stone sounds nice
Could I have damaged something by leaning into the engine to replace the glow plugs. I may have smushed something on accident near the ip if I slipped or leaned to hard? Could that be the case?
Also the coffee looking can on drivers side looks as if someone squeezed it really bad. Does this have anything to do with the vacuum pump?
I was reading this post and its exactly they way it feels for mine.
Also will fixing the vacuum pump fix my stiff brake pedal as well.
2 birds with one stone sounds nice
Could I have damaged something by leaning into the engine to replace the glow plugs. I may have smushed something on accident near the ip if I slipped or leaned to hard? Could that be the case?
Originally Posted by tjc transport
hard shift as in it bangs into gear, or hard shift as in it will not shift unless you let off the throttle??
if it is a bang into gear hard shift, that is normal with the C6. if you adjust the modulator valve for soft shift, you will burn up the trans.
if it is a will not shift till you let off the throttle hard shift, it is most likely a vacuum pump going bad.
the vacuum pump need to supply around 21 inches of vacuum for the trans to shift properly.
if it is a bang into gear hard shift, that is normal with the C6. if you adjust the modulator valve for soft shift, you will burn up the trans.
if it is a will not shift till you let off the throttle hard shift, it is most likely a vacuum pump going bad.
the vacuum pump need to supply around 21 inches of vacuum for the trans to shift properly.
Lead Driver
Joined: Nov 2003
Posts: 6,900
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From: Campbell River, B.C.
If the transmission is holding low gears for too long, and shifting hard once it upshifts, AND you have no powerbreaks, than its most likely a vacuum problem.
Check the alternator belt, vacuum pump beld (driven off alternator), and check for vacuum at the break booster line. There should be a powerful enough vacuum to stick the line to your palm.
The coffee can on the fender is a vacuum reservoir for running accessories and other vacuum operated devices. If it is damaged or rusted (happes often) it will bleed air into the vacuum system and effectively eliminate the vacuum if the leak is big enough. I would try to bypass this first to see if its the source of the problem.
Check the alternator belt, vacuum pump beld (driven off alternator), and check for vacuum at the break booster line. There should be a powerful enough vacuum to stick the line to your palm.
The coffee can on the fender is a vacuum reservoir for running accessories and other vacuum operated devices. If it is damaged or rusted (happes often) it will bleed air into the vacuum system and effectively eliminate the vacuum if the leak is big enough. I would try to bypass this first to see if its the source of the problem.
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Well the hose that goes from the vacuum pump to the tree i guess its called. I unloosened a couple of them to see if they would stick to my finger and none of them would. I checked the hoses attached to something very close to the vacuum reservoir and theres absolutely nothing at all.
My problem is this hard upshifting happened after i changed my glow plugs.
I searched and found someone that had the exact thing happen to him as well. Same tranny same stuff.
My problem is this hard upshifting happened after i changed my glow plugs.
I searched and found someone that had the exact thing happen to him as well. Same tranny same stuff.
Lead Driver
Joined: Nov 2003
Posts: 6,900
Likes: 3
From: Campbell River, B.C.
Its also possible that you might have disturbed the VRV (vacuum regulator valve) on the injector pump. Its on the driver's side and it tells the transmission how heavy your foot is to modify transmission operation accordingly. The kickdown rod might have also been bugged. I still think There is a vacuum problem if you noticed braking problems start at the same time. The only thing left to see if the vacuum pump is working is to try and get a vacuum directly from the pump itself (while engine is running).
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