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less braking power

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Old Dec 28, 2009 | 12:50 AM
  #1  
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From: Malahat/Cowichan Valley
less braking power

Fellas,
More and more i am feeling worse braking. Sometimes it is like a new truck and other times it goes way down. The fluid level is good. But the other day i got out of the truck and heard a hissing sound. I threw the hood up and it is coming from the booster area. Could it just be a vacuum line leaking? Where could it leak from around that area if it is not a line. The hissing lasts for a few seconds and is gone.
 
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Old Dec 28, 2009 | 12:54 AM
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Does it hiss while you are holding the pedal down. It's either the booster or a line or plastic t connection somewhere. Look very closely at all hose and connections.
 
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Old Dec 28, 2009 | 12:54 AM
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From: Faibanks Ak.
The brake booster itself can leak and make a hissing sound usually more prominent when the brakes are applied.
 
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Old Dec 28, 2009 | 12:56 AM
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well i definitely cant hear it with the truck running but i will have my dad help me test it with some soapy water to find the gremlin! Heres to hoping it is a fitting or hose! hahaha
 
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Old Dec 28, 2009 | 12:58 AM
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Kill the engine and apply the brakes and hold if it is the booster you should hear the hiss inside the cab with the brakes applied.
 
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Old Dec 28, 2009 | 01:55 AM
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I was just coming here to post something similiar. We have had a our junker 85 f250 for a few weeks now and just got done overhauling the engine and fluids and the brake light went on by itself for the first time since we had it

I can't say we know what "normal brakes" feel like on this truck, but haven't noticed any major issues on that front.

Anyways the truck had been in the garage for a few days getting worked on and my brother started the truck while I was standing near the drivers side with the hood up.

He turned off the engine rather quickly after startup for whatever reason and that is when I could hear a hissing noise for a good 5+ seconds until it went away. It sounded like it was coming from around where the brake fluid goes into, high and near the firewall.

Looks like I need to get a vaccum gauge and start at the pump since I have no clue about the history of my setup. Altough now that I have read a bit, seems I have a leak for sure reguardless.
 
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Old Dec 28, 2009 | 02:23 AM
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I don't think soapy water is a good idea. First, its vacuum, so you won't see any bubbles. Second, you could end up sending that soapy solution through the vacuum pump and shorten its life span.
 
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Old Dec 28, 2009 | 02:47 AM
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haha crap david, i didnt think of it that way!!! haha, is there a better way to pinpoint the problem?
 
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Old Dec 28, 2009 | 06:41 AM
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First thing I would try is to pull the vacuum line from the vacuum booster about a minute after shut down (or after the hissing noise stops).

A good system will have a nice hiss when you break the seal and should hold a vacuum for several hours after shut down. This will confirm if this is indeed a vacuum problem.

Easiest way to track it down would be to try and follow the hiss by ear to where its coming from.

Could be a rotted line, loose connection, rusted vacuum booster, rusted vacuum reservoir chamber (coffee can on the driver's side plastic inner wheel fender).

Just remembered you have a C6 transmission. Is it still shifting normally?
 
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Old Dec 28, 2009 | 09:37 AM
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I am working on a crashed hard drive, I may have recovered a brake booster test but I won't know till later.

A vacuum gauge is the best tool for this.

Remove all lines from the vacuum tree except the vacuum pump line and block the ports with the vacuum gauge on one of them.

Read the vacuum level.
Now reinstall the vacuum lines one at a time.
When you start showing low vacuum, you have found the offending system.
 
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Old Jan 4, 2010 | 11:23 PM
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pretty sure it isnt a vacuum issue, zero shifting problems and i have vacuum for over a day later. Not sure now what the heck the noise is. Anything else make that noise in that area? Also i have no coffee can?!
 
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Old Jan 4, 2010 | 11:33 PM
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From: Faibanks Ak.
I guess it must be telling you it wants hydroboost now.
 
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Old Jan 4, 2010 | 11:36 PM
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hmmmm whats that? i know it is a booster for the brakes but what is the diff?
 
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Old Jan 4, 2010 | 11:48 PM
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Hydraulic instead of vacumn runs off your power steering. direct bolt in with ford parts off a F450.
Your truck is saying I'm looking good, running goog just a few more bucks and I'll stop good too. IT's only money.

Seriously though it is a great upgrade, way more stopping power.
 
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Old Jan 4, 2010 | 11:50 PM
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From: Malahat/Cowichan Valley
Originally Posted by starmilt
Hydraulic instead of vacumn runs off your power steering. direct bolt in with ford parts off a F450.
Your truck is saying I'm looking good, running goog just a few more bucks and I'll stop good too. IT's only money.

Seriously though it is a great upgrade, way more stopping power.

ahhh very cool. I will see what i can do about that, i know of a jy that has a ford section that is fat right now. Same years or is it a range like usual?
 
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