The brakes on my volvo xc70 2005 are hard to push and dont have any assistance. It make a swish sound when I push the pedal. it does brae though but I have to push really hard! Might it be the master vac?

With the engine off, put your foot on the brake pedal and press down. The pedal should go nowhere. With foot still pressing on pedal, start the car. The pedal should move down. If not, could be an issue with the servo such as a cracked / leaking air hose or an issue with the master cylinder seals.

vacuum leaks can make booster loose power assist. if pedal intermediately hard to push the booster might be bad. if the pedal goes to the floor and you dont have brakes might be the master cyl

just replace the brake vacuum may it is loose of air seal., replace your hydrovac.

the brake booster will make the brake pedal hard to push. they get that way usualy when they loose there vacume. if you dont hear a vacume leak with engine running then i would start with replacing the booster

Hi,
Start your Volvo up push you break pedal down, shut your Volvo off with the break pedal down. If the booster is good the pedal should NOT go towards the floor board. It should hold in place.
If the pedal moves towards the floorboard the booster is leaking.
Wayne

HI this sounds like the vacuum booster has a leak in the diaphragm. That is why you hear that sound when you push on the brake pedal. With out the vacuum to help this leaves you with a very stiff brake pedal. You will need to replace the Booster which is located behind the brake master cylinder and on the firewall. Good luck

Hello moonc40: My name is Roger and I will help. With the engine off step on the brake a couple of times. Hold your foot one the brakes and start the engine. The pedal should drop a couple of inches. If it does not then your vacuum booster is most likely the problem. With out the booster assist your brake pedal will be extremely hard to push. If you hear a hissing sound inside of the vehicle when the brake pedal is pushed? The problem is the booster.Should you need further help please just ask. Please rate the answer this way I know it was helpful. Thank You for using Fix Ya. Roger

brake master cylinder is mounted on brake servo under bonnet . remove the metal brake pipes going to it remove 2 nuts holding it to servo remove from car fit new one fill with brake fluid dont connect pipes yet have assistant pump pedal when fluid flows out of all ports on cyl get assistant to hold pedal down now fif pipes and secure try pedal if it feels firm job done if not you willneed to bleed the whole system

you either have a bad brake booster or no vacuum to the booster.Check for vacuum while running if you have vacuum replace the brake booster :)

When you press on the brake? Have your brake vacuum assist checked. It,s that bigspaceship looking thing between the brake master cylinder an firewall. good luck and be safe.