could this be the cause of my problem? is it safe?

[thegawd]

if the vacume booster is leaking bad you will hear it in the cab as it leaks around the diaphram of the plunger where the peddle hooks up. it wont apply but on an obd2 you can watch the short term and long term fuel trims rise all the way up to 100% if you hold the brakes long enough. then it will fall.on its face and possibly stall. I had it fail in my burb and it wasnt fun coming up to a stop sign.... but it turns out it was leaking prior to the catastrophic leak, I just couldnt hear it as after I replaced the booster my truck ran much better.

Al

 

[sntrym]

I'm starting to wonder if it's the intake manifold gasket. Any tips on checking that?

Starting fluid would be easiest. Just spray around the gasket area. Use the red nozzle to keep the spray down.

 

[Schurkey]

Connect a scan tool, look at the data stream.

Verify fuel pressure.

Don't make this harder than it has to be.

 

[91bbc]

Connect a scan tool, look at the data stream.

Verify fuel pressure.

Don't make this harder than it has to be.

I don’t have a scan tool for obd 1. I think your right about keeping it simple though, I’m just going to take it to a shop and let the pros figure it out.

 

[JonP]

The opposite side of this diagnosis would be to smoke the intake. This is non running and checks the entire vacuum system, by filling the closed system with ester smoke, any escape route will be exposed. you can buy or make a smoke machine. definitely check YouTube for use and kit construction.

 

[Steve A]

I had a different make vehicle do that once and it turned out to be the IAC.

 

[91bbc]

So I took it to the shop and they used a smoke machine and used starting fluid to try the find the leak. They could not find it. They replaced the iac and it helped smooth things out a lot. Dropped the idle by 100 (idles at 1k now).

They did not hook up the truck to a computer, and I dont have one.

While the truck was there they flushed the brakes. Now my brake light comes on when I press the brakes, and has nothing then all of a sudden very strong brakes when I hit the pedal. It was also leaked from swollen seals between the master and reservoir. They said sometimes then they flush the brakes the seals leak in the master and I should replace it.

Since the booster looks like it is had a leak at one point, but holds vacuum and seems to work just fine is it possible replacing it and the master could solve my high idle? They said they tested the TPS and it was working perfectly, and I think its the last sensor that could affect my idle. I did the iac reset sequence with the new iac btw.

I'm going to try removing the stupid rear abs this weekend and see if the brake light thing goes away. Maybe there is air trapped in there.

Thanks!

 

[Schurkey]

Take the vehicle back to them, and demand that they bleed the system PROPERLY. Based on your description of the leak between reservoir and cylinder, they potentially used the WRONG ADAPTER to connect a pressure bleeder. If so, they owe you a repair for that--either re-sealing the reservoir, or more likely, a replacement reservoir/cylinder assembly. Make sure they use the correct tool next time.

Consider FIXING the ABS (assuming there's something actually wrong with it) instead of disabling it. Maybe all it takes is to open the bleeder screw on the ABS unit itself.

Pinch the hose to the brake booster, see if the idle changes. If it does, the booster or the hose is defective. If it doesn't, replacing the booster isn't going to help.

You went there complaining of idle problems, and they DIDN'T connect a scan tool? On second thought, those folks are morons. Maybe you shouldn't go back. But obviously, you need a partial refund for the horseshit work they did.

 

[red98]

You went there complaining of idle problems, and they DIDN'T connect a scan tool? On second thought, those folks are morons. Maybe you shouldn't go back. But obviously, you need a partial refund for the horseshit work they did.

THIS as soon as I read that they didn't even plug it in, I'd never bring them anything to work on again.

They obviously just took "the customer's" (91bbc's) ideas, the smoke test, and the flammable gas to see if the idle changes, and tried them out. They're one of those "we do what the customer tells us to do" shops, instead of actually trying to diag the issue.

That's why a lot of the time its just best to tell them the symptoms and tell them you need it diagnosed, if you go in saying you need a smoke test done, they'll smoke it and thats it. Not to mention they essentially admit to damaging the brake system by flushing it (incorrectly), then insist its normal? WTF?

I don't even know if I'd wanna drive the truck in its current state.

 

[91bbc]

Take the vehicle back to them, and demand that they bleed the system PROPERLY. Based on your description of the leak between reservoir and cylinder, they potentially used the WRONG ADAPTER to connect a pressure bleeder. If so, they owe you a repair for that--either re-sealing the reservoir, or more likely, a replacement reservoir/cylinder assembly. Make sure they use the correct tool next time.

Consider FIXING the ABS (assuming there's something actually wrong with it) instead of disabling it. Maybe all it takes is to open the bleeder screw on the ABS unit itself.

Pinch the hose to the brake booster, see if the idle changes. If it does, the booster or the hose is defective. If it doesn't, replacing the booster isn't going to help.

You went there complaining of idle problems, and they DIDN'T connect a scan tool? On second thought, those folks are morons. Maybe you shouldn't go back. But obviously, you need a partial refund for the horseshit work they did.

Yep they are idiots and ripped me off and I don't want to take it back. I live up a tight canyon roads with blind turns. How do I fix this thing? I have to drive 1,600 miles possibly towing 18,000 pounds next month.