If the pedal effort when braking is noticeably greater than usual, check the brake booster with the vehicle stationary.
You will need: a flat-blade screwdriver and a rubber bulb.
1. With the engine off, press the brake pedal five or six times. Keep the brake pedal depressed and start the engine. The brake pedal should move forward. If this does not happen, check...
2. ...the tightness of the vacuum hose fit in the intake pipe...
3. ...and a vacuum booster.
4. To check the operation of the check valve, remove the battery shelf (see "Removal and installation the battery").
5. Remove the vacuum hose nipple from the brake booster sealing bushing hole…
6. … remove the vacuum booster hose from the bracket on the rear wall of the master brake cylinder reservoir…
7. …and move the hose away.
8. Insert the bulb tip firmly into the end of the vacuum hose that connected the hose to the vacuum booster and squeeze it. Air should escape from the bulb through the valve.
9. Release the bulb. If it remains compressed, the valve is OK. If there is no bulb, you can blow through the valve with your mouth.
10. If the check valve leaks air in both directions, replace the vacuum hose assembly with the valve, to do this…
11. … remove the vacuum hose fitting from the inlet pipe opening and remove the vacuum hose assembly with the check valve.
12. Install the parts in the reverse order of removal.