hard brake pedal
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hard brake pedal
my dad's 05 f250 super duty 4x4 has a hard brake pedal but it only does it at road speeds, he said it started after he had a tune up done i have checked it over and can'r find anything unhooked i think it may be a prob with the booster but not sure
Senior User
Joined: Mar 2015
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From: Yonkers, NY
Gotta be something with the vacuum to the booster. Sounds like he's losing boost. Check the obvious first, like the condition of the big vac line to the booster. You can try spraying some carb cleaner around the booster and the vac line with the truck idling. If you spray where there's a vac leak the engine RPM will pick up. Sorry I can't help more without the truck in front of me.
Fleet Mechanic
Joined: Nov 2011
Posts: 1,825
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From: Land of Taxes
As NYC says something got disconnected or damaged during the tune up(possibly, or its just a coincidence). Could be a fractured plastic connection or a split or collapsing vacuum hose. Check the hoses carefully and the one way valve and the grommet on the booster.
At speed your vacuum signal is lower so its likely a small leak which is not as prevalent at high engine vacuum periods, such as at idle. If you or your dad don't have mechanical skill simply take it back to the mechanic who performed the tune up. Don"t be accusatory, just state the problem and let them tell you what they find.
Careful, I wouldn't use carb spray if its a diesel. It can flash like starting fluid which = shattered pistons n rings.
Do you notice erratic idling or stumbling or anything other than a stiff pedal?
At speed your vacuum signal is lower so its likely a small leak which is not as prevalent at high engine vacuum periods, such as at idle. If you or your dad don't have mechanical skill simply take it back to the mechanic who performed the tune up. Don"t be accusatory, just state the problem and let them tell you what they find.
Careful, I wouldn't use carb spray if its a diesel. It can flash like starting fluid which = shattered pistons n rings.
Do you notice erratic idling or stumbling or anything other than a stiff pedal?
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