Should a brake booster hiss?
A hissing noise is usually the brake booster leaking air. There could be a leak in the vacuum line, the booster diaphragm, or the master cylinder. A small leak could cause a hissing sound when you press on the brake pedal or let off.
Does a bad brake booster make noise?
You hear a hissing sound In some cases, you can hear problems with a brake booster. For example, you might hear a hissing noise after you step on your brakes and then release them. If you hear hissing, then the booster, or one of its seals or connections, might have a crack, break or leak.
Why does my brake booster make noise?
A problem with the booster diaphragm triggers the failure of the brake booster. A leak of air from the master cylinder gasket into the brake booster. Many vehicles that have brake boosters come with a piece of foam that blocks the hissing sound. If the foam is missing or damaged, you may hear the hissing sound.
Why does my Volvo 740 make a hissing sound?
Leaking Sound from Heater Controls. [John Sargent] One of my 740s made a hissing sound from under the dash in the area of the heater temperature control lever. The manual heater control assembly supplies vacuum to the under hood heater valve to shut off coolant flow to the heater core in the cold position of the control lever.
How to Shim the AC clutch on a Volvo S60?
Here’s how to shim the AC clutch on an S60. Here’s how to shim the AC clutch on an 850, V70/XC70 up to 2000, S70, or C70. Do not use the high pressure port that is right up front above the radiator. That’s the high side for shops with pro AC refill equipment. Instead, move a couple items out of the way and use the AC low port.
What causes a Volvo XC60 engine to stall?
The pumps electronic module might not operate as intended, which could cause the engine to stall. Some cars have had problems with their seatbelts. Under certain side-impact scenarios, its possible that the side panel on the drivers seat might contact the seatbelt release button and cause the belt to detach.
Where is the vacuum hose on a Volvo?
Leaking Sound from Under Dash. That vacuum leak is almost certainly your floor/defrost diaphragm. It is on the left side of case just above the accelerator pedal. This diaphragm unit is double acting, i.e. it has vacuum to pull it both ways, blue hose for defrost and yellow for floor.