Congratulations!

now you just have to figure out exactly what’s causing it

I’d say it’s your hose I would attempt to replace it

how does it run with it plugged ?

 

I will replace it. Put i think that the other side going in the brake booster is the problem. The white piece does not go all the way in. It sticks out. You can see in the images above and tell me what you think.

 

Does it feel like it’s super loosely in there. Mine has a little play but it’s not super loose.

you could always try spraying the break clean a tad on there with it running and see if it changes your idle

You could also remove your hose completely and inspect it close to see any cracks or holes

that could rule out the hose and you could try replacing the check valve

 

When I spray brake clean in that area it changes my idle. And if i keep spraying the engine almost stalls. its not super lose there is some play like you said

 

So I’ve been looking around at autozone and oreily and I don’t think either sell just the check valve. So that might be a pain to replace without replacing the whole booster.

Im assuming you unplug the hose on the break booster side not the intake manifold side so if that’s the case your probly right and it’s not the hose. Look around online watch some tutorials because I myself have not had to do that before so I would educate urself on the “break booster check valve”. I think it’s worth your time to educate your self and see if it’s possible to buy and replace just the check valve instead of replacing the whole booster.

 

No i unplug the side of the intake manifold. Does that change the game now?

 

The only thing it changes is that your hose going to the break booster could be the leak don’t worry

I would take the hose off the check valve, since you’ll have to do it to replace it anyways. Closely inspect it if there are any cracks. Just make sure it’s not ur hose leaking before you go replacing the check valve.

hoses get brittle and crack when their older it’s pretty common

 

hose looks good but i found a check valve and grommet for only 6$ at auto zone

 

Definitely worth a try

 

I cant find any cracks. I think the black piece may be worn and not sealing the valve

 

Same concept, rubber dries up and brittle and cracks doesn’t seal

That check valve is just plastic and rubber probly 18 years old :)

see what happens when you replace it

 

you know the little o ring garmmet that goes on the brake booster where the check valve goes? Could that be worn and not sealing it all the way? It has no cracks as far as i can see

 

Well it could possibly not be making an air tight seal

either way you’re gonna want to try replacing that and your hose before replacing the break booster

we know that’s where the leak is

it can only be the hose, check valve, or break booster

 

Cheap **** first lol. I think i can rule out the hose but ill replace it anyways. I'm thinking check valve and garmmet

 

Trust your instincts

 

well they didnt have a hose at autozone. I got the check valve garmmet and fuel trims are bad still. When I plug intake manifold side with duct tape fuel trims go to normal. I don't understand😠

 

They don’t have a hose that size? They should stock rubber hoses like that, maybe go to a diff one. All you need is same diameter and length

 

so what other options are there? After replacing hose. I don't think the hose is the problem. Has no cracks or rips.

 

Your break booster diaphragm could be leaking. The diaphragm is inside the black housing. When it goes bad air leaks from inside the housing and through the check valve to the hose and into your manifold. It works by creating a vacuum inside that housing giving your breaks a little power behind them.


i didn’t really suspect this bc the idle changes when you spread break clean on the outside of it

 

I'm thinking too much air from a leaking diaphragm too. The idle barely changed when spraying that brake clean. Well... This is great i have to get a new brake booster and pray it works. ):

 

Everyone on quora is saying leaking diaphragm but my pedal is not hard though?

 

It just makes me skeptical because if it changes the idle if you spray break clean on the outside then that points to the hose or check valve

 

I think the brake clean was getting in where theres play like you said. Not the hose. I replaced check valve so it is brake booster

 

As long as you think you ruled out the hose and check valve

like I said I would trust ur instinctsbecause you’re the one in front of the truck