Vanning.com logo
Boxdin
Site Navigation


Advertisements
Recent Posts
Progress on the "Fish Out of Water"
by Leakbox - November 28th 2020 12:58 am
Subwoofer direction in cargo van
by lukester - November 27th 2020 11:42 pm
1977 chevy van
by SDMickey - November 27th 2020 9:18 pm
88 G20 slow resurrection
by frscke1 - November 27th 2020 4:53 pm
Slider mechanism
by frscke1 - November 27th 2020 11:37 am
Featured Links
Vanning.Com is a an authorized Amsoil Dealer


Previous Thread
Next Thread
Print Thread
Rate Thread
Filter in Brake Booster Vacuum Line?
#766136 October 06th 2020 11:18 pm
Joined: Oct 2020
Posts: 4
S
stranger
OP Offline
stranger
S
Joined: Oct 2020
Posts: 4
My daughter says her van stalls when coming to a stop after driving for a while at highway speeds. She says the van starts fine, runs good and is fine while she drives on the highway. if she doesn't stop, all is good. The problem appears when she needs to stop, the engine dies. I drove the van around the city, no issues but she says the problem is more apparent when the engine is hot after hours of highway driving (lots of hills/mountains on our highways here in British Columbia).

Sooo, I was wondering if the brake booster has a vacuum leak, I have not tested it yet, but when I looked at the service manual, it says the van should have a filter in the vacuum line going to the brake booster. Her van is on the third owner, and it appears the filter is not installed. The van is a 1989 Dodge B250 and has a 318 with Holley Fuel Injection.

Does the filter matter? Any hints on how to test the brake booster for a vacuum leak? Is that uncommon?

Thanks in advance,
Sierracierra


1989 Dodge B250 Camper Van 318 Cubic Inches or 5.2 Litres
Re: Filter in Brake Booster Vacuum Line?
sierracierra #766863 October 25th 2020 9:57 pm
Joined: Mar 2007
Posts: 4,401
Likes: 2
pooh-bah
Offline
pooh-bah
Joined: Mar 2007
Posts: 4,401
Likes: 2
That filter may actually be a filter for keeping oil vapors out of the brake booster, or a one-way valve depending on what you've got. Some vans even have both.

Since the brake booster is full of vacuum, once the engine shuts off, atmospheric pressure pushes any fumes in the manifold into the booster, where the rubber parts can be attacked over time.

You could attach a hand operated vacuum pump to the booster to see if it holds vacuum.

As for substantial vacuum leaks in out of the obvious places, try the charcoal evaporative canisters and their hoses. Those hoses frequently turn mushy and split wide open. The master canister (with the vacuum actuator on top) has a rubber diaphragm inside which can rupture, causing a very substantial vacuum leak. When you attach a hand vacuum pump to that actuator, it should hold vacuum.

Among my favorite stealth failures on vintage vans is the fuel tank cap. It has a breather valve built in. Driving at highway speeds, you develop maximum vacuum from the fuel pump. If the breather valve in the cap fails, you will starve the carb for fuel, and can literally collapse a tank. All you need to do to eliminate that as a culprit is to try opening the cap when you've got a stall and listen for a "whoosh" of incoming air to replace the built up vacuum. It's possible to drive with the cap partially cracked open too, though that does have some potential safety issues.


-It's been such a LONG TIME... BlueShift>> 1981 Dodge Ram B250 Custom Sportsman Maxi Van


[Linked Image]

It's what you learn after you know it all, that counts...

Are you living to work, or working to live?

[Linked Image]

Learning from my own mistakes is good, learning from yours would be much better! [Linked Image]

Moderated by  Astro, Ram4ever 

Link Copied to Clipboard
Donate


discovery
Who's Online Now
0 members (), 3 guests, and 2 robots.
Key: Admin, Global Mod, Mod
Newest Members
ChrisJB84, Cec813, chefG, Shaguadelic, JDHall
11692 Registered Users
Top Posters (30 Days)
SDMickey 137
frscke1 62
NateB 29
Forum Statistics
Forums68
Topics38,281
Posts537,997
Members11,692
Most Online177
May 8th, 2013

Powered by UBB.threads™ PHP Forum Software 7.7.4