Brake vacuum problem solved perhaps

[JLEONARD]

Hopefully anyway. I have been losing vacuum partway thru a braking event when the weather is really cold... say below 20 degrees or so. Plus all even when the temp is warm, I hear the vacuum leaking out as I shut the truck off with my foot on the brake.

I was thinking maybe a booster gone bad, but I wanted to identify it positively as bad before I spent the $$ and time.

So I used my sons mighty vac hand pumpand tested the system last night... hooked into the check valve and pumped it up. It would slowky bleed out.

My son suggested removing the check valve and seeing if it worked properly.

Bingo. Found a very small crack in the small nipple that feeds the switch that's up under the fender.

Makes sense that it would leak more in cold weather being plastic.

Since it's a dealer only item (at least according to NAPA) I'll have to wait till today (hopefully) to get a new one.

I taped mine with electrical tape for now, and it's much better this morning.

Just thought I'd pass this on.

Jay

 

[Grey Wolf]

Jay,



My sons '90 had a vacuum leak also, we checked all the areas you did too. His leak happened to be the vacuum switch that tells the ABS light to come on. It was a pain to go through the whole system but at least we became more familiar with the system and now we understand how it works, we hope

 

[ARhine]

depending on dealer price alittle JB weld in the crack might fix it right up. On different plastic parts what I have done is put the JB on there then draw a vaccum on it with the hand pump for a short period of time to draw the epoxy into the cracked area.

 

[JLEONARD]

alittle JB weld in the crack might fix it right up

Epoxying it will be my next to last choice... last choice being to not drive it.

I consider epoxy a fix if I can't find a replacement... . or tempoary at best.

That's my opinion... I know I've fixed many things with epoxy, but it's my brakes, and I drive fast, so I don't want any "self inflicted" :-laf screwups.

Right now it works with the tape... . better than it has in a long time.

1st NAPA universal was too small. I'll try another NAPA style tomorrow am if they have one, otherwise I'll wait the 2 days for the dealer part.

I think my son said it's only about $10 or so... . but I'll have to go to the dealership and show them which part I need because they couldn't figure out which one it was... . duh!

Jay

 

[BJMarshall]

Jay,

I got one at a local parts store. I think it was car quest. They had it in stock.

 

[JLEONARD]

I just installed the new Mopar check valve and made a short trial run.

It appears that the problem is solved, but I won't know for sure until the temps get really cold agasin... also it's possible there is another area to look at, but at least the check valve is good now!

Part number is 1-04485491

I'll epoxy the old one so I'll have a spare I'll never need.

Jay

 

[drives mopars]

jim and forrest where is this thing

where is this valve

did u say on drivers fender

 

[JLEONARD]

The check valve is in the fitting that attaches to the booster.

My brakes are better, but I still have a loss of vacuum on cold days.

More testing this week I guess.

Jay