2014 Chevrolet Silverado 1500 engine failure

15 Z71 · February 11, 2017

This is the first time I have heard of this. Is this not very common?

HondaHawkGT · February 12, 2017

Not common but it's a matter of when, not if, the vacuum pump fails. It could fail at 20k or 120k miles but it seems to do it with little warning before hand. It doesn't seem worth the risk imo.

Any know what the GMT900's used for a vacuum boost? It wasn't a hydroboost system was it?

shrekmoose · February 12, 2017

ok got to looking at it today, The pump is the only thing that feeds vacuum into the brake booster if someone could make a line and a harness for the vette pump the pump could be mounted where the 2nd battery tray is and the line run right up to the brake booster.

FL335i · February 13, 2017

How about a part # for the vette pump? Also, I like the question about what the previous gen trucks used for vacuum? They had cylinder knock out technology too...

GMC2015 · February 13, 2017

I'm pretty sure the GMT900s used vacuum from the engine for the brakes using a plug that was in the back of the intake manifold.

shrekmoose · February 13, 2017

I'm pretty sure the GMT900s used vacuum from the engine for the brakes using a plug that was in the back of the intake manifold.

I would much rather do this than anything would like to just pull the whole pump off plug the oil holes and be done. Truck is going to have afm tuned out anyway any connection that throws a light for the vacuum pump not being there could be pluged as well.

GMC2015 · February 13, 2017

I would much rather do this than anything would like to just pull the whole pump off plug the oil holes and be done. Truck is going to have afm tuned out anyway any connection that throws a light for the vacuum pump not being there could be pluged as well.

The real question is who is willing to tap into the back of the manifold, make/mold a custom plug, and run a vacuum line to the brake booster?

shrekmoose · February 13, 2017

i havent looked to hard at this is there no way to pull vacuum from motor without drilling any holes? I know followed a link to where a guy was putting a genv motor in a old camaro I think it was but he was planning on using some kind of valve in the intake for vacuum but never did see anymore about it.

shrekmoose · February 13, 2017

My first choice for Power Brake Vacuum will be the EVAPORATOR/PURGE CONTROL VALVE (Number 36 on the diagram). This is an electronic controlled valve used to allow fuel tank fumes to enter the intake. It is part of the emissions system. Since I am not using this valve I hope to get sufficient vacuum for the brake booster from its port. I won't have my wire harness for 6 weeks, so a test will have to wait. I spoke with Jared at ICT billet and I ordered part number 551359 (LT L83 L86 LT1 Billet Purge Solenoid Delete Plug Evap Block Off Gen V Intake Manifold). My plan is to drill and tap ICTs billet aluminum plug for a 3/8 fitting to run a vacuum line to the booster. As soon as I get it install I will post photos.

Attached Thumbnails

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found it thats from ls1 tech not sure where that valve is located cant get the picture to blow up on my computer.

HondaHawkGT · February 13, 2017

Alright I looked at the datalogs from my Autocal on EFI Live. It looks like my lowest manifold pressure was roughly 24 kPa (AFM disabled). Atmospheric pressure is 101 kPa. So 77 kPa is approx 22.7 inHg.

Any advantage of using the purge valve over the PCV barb on the side of the manifold?

pickmeup · February 14, 2017

Jeg's makes inline filter catridge screens for about 40.00. they filter to 140 microns . Seems like if installed down stream of vac pump it would add a good level of safety to engine.

shrekmoose · February 14, 2017

Alright I looked at the datalogs from my Autocal on EFI Live. It looks like my lowest manifold pressure was roughly 24 kPa (AFM disabled). Atmospheric pressure is 101 kPa. So 77 kPa is approx 22.7 inHg.

Any advantage of using the purge valve over the PCV barb on the side of the manifold?

i guess i havent thought of the pcv valve the only issue i see with that is with the oil vapors being in the brake booster if im thinking of the correct pvc valve. That said im not 100% sure what the purge control valve even does. just think I remember when the first 5.3s came out and we all thought it was high tech lol

Hoginedgewood · February 14, 2017

I think I will just keep an ear out for odd noises. I like how quiet my new truck is. I would hope a dying pump would make some noise for a while before it grenades.

It cracks me up when I see people stuck in the middle of the road, wheel fell off. Ball joint failed. Wouldn't you think there was an odd noise for the last several months, play in the wheel or some clue?

Not saying the vacuum pump will give a noise, but I will hope for the best before I spend hundreds on this tinfoil hat procedure.

07Softail · February 14, 2017

These engines don't make enough vacuum for the brakes, That's why they use pumps for the brake booster.

RT

Willilo · February 15, 2017

I have 62000 miles on my sierra. No real issues. What about just replacing the pump with a new one as a preemptive strike? What would that set you back? Is the pump failure as inevitable as it's made it out to be on this thread?