Replacing Brake Fluid W/o Bleeding Unit
Replacing brake fluid without bleeding unitSpecial tools: 115 8147, 999 2809
Replacement guidelines
Replacing brake fluid is recommended every 48,000 km (30,000 miles), or every other year. In cars where the brakes are used and often (e.g. in hilly areas or in tropical climates where humidity levels are high), fluid should be refaced each year.
Background
The reason that brake fluid should be changed is that brake fluid is hydroscopic: that is, it absorbs water molecules from the air. Water is partly absorbed through the brake hoses and brake fluid reservoir, which are made of rubber and plastic respectively, and are to some extent permeable to water molecules.
Increasing the water content of brake fluid means that the brake fluid's boiling point falls dramatically and that corrosion forms on the braking system components. The result is that the braking system is damaged and its functioning seriously impaired.
Note: Use only Volvo original brake fluid marked DOT 4+. Never re-use brake fluid. Always keep brake fluid in its original packing, well sealed.
Note: Check continuously that there is enough brake fluid in the brake fluid reservoir when replacing brake fluid.
Preparations
- Ignition off.
- Jack car up and remove wheels.
- Clean around brake fluid reservoir cap. Get a drain bottle and hose to collect brake fluid in.
Replacing brake fluid, front
- Remove protective cap from bleed nipple.
- Connect drain bottle hose. Open nipple approximately one turn.
- Push brake caliper piston to bottom of caliper using a bolt clamp, see illustration. Leave bolt clamp in the pushed-in position.
- Push brake pedal right down and hold it there for approximately 2 seconds before releasing it. Repeat until 2-3 dl (0.2-0.3 US qt) of brake fluid has drained off.
- Close bleed nipple while holding brake pedal right down.
- Remove hose and re-fit protective cap.
- Remove bolt clamp from brake caliper.
- Depress brake pedal a few times.
Replacing brake fluid RH front
- Repeat steps (LL3-5), on the front RH brake caliper. Then continue as per instructions below.
Removing brake pad LH rear
- Remove brake pad brake caliper.
Replacing brake fluid LH rear
- Remove protective cap from bleed nipple.
- Connect drain bottle hose. Open nipple approximately one turn.
- Push brake caliper pistons right down into caliper, using tools 999 2809(x 2). Leave tools on calipers.
- Push brake pedal right down and hold it there for approximately 2 seconds before releasing it. Repeat this until 2-3 dl brake fluid has drained off
- Close bleed nipple while holding brake pedal right down.
- Remove hose and refit protective cap.
Remove:
- Remove tools from brake caliper.
Removing brake pad LH rear
- Install brake pad as per Replacement of components.
- Depress brake pedal a few times.
Replacing brake fluid Rid, rear
Repeat steps Brake fluid, replacement with bleeding unit.
Finishing work
- Depress brake pedal repeatedly until brake pistons return to normal position.
- Check brake fluid level and install reservoir cap.
Clean off any brake fluid spillage with lukewarm water and car-wash shampoo.
Installing wheels
Make sure that brake disc and rim contact surfaces are clean.
- Grease hub center rim guide with anti-rust agent 116 1038-3.
- Re-fit wheel.
- Tighten nuts hand tight. Then tighten in a star pattern to 110 Nm. If tightening with a nut wrench, use torque bracket.
Note: Tightening nuts in a star pattern to a specified torque is important to prevent stresses arising in the brake disc.
Replacing and cleaning brake fluid reservoir
Preparations
Clean around brake fluid reservoir cap, connections between reservoir and master cylinder and any hose connections to prevent dirt entering brake system. Put rags under the hydraulic unit to protect painted surfaces against brake fluid spillage.
Removing brake fluid reservoir
Ignition off.
- Disconnect connector from brake fluid level sensor.
- Drain brake fluid reservoir.
Remove:
- Bolt from underside of brake fluid reservoir.
- Brake fluid reservoir from master cylinder.
- Block hose to clutch cylinder with hose pliers.
- Disconnect hose from brake fluid reservoir and plug connections to prevent dirt entering system.
Cleaning and checking
- Inspect brake fluid reservoir, level sensor, non-return valves and seals.
Use new seals if necessary.
Clean carefully any components not being replaced of old brake fluid and dirt using new brake fluid.
Installing brake fluid reservoir
Check that there is no dirt in the connections.
- Grease O-rings and any hoses with brake fluid or glycerine.
Note: Do not use cleaning solution for greasing hoses. Use brake fluid or glycerine.
Install:
- Brake fluid reservoir from directly above.
- Bolt on underside of brake fluid reservoir. Tighten to 3.5 Nm. Fill brake fluid reservoir with new brake fluid. In cars with manual transmission: Connect hose to brake fluid reservoir. Remove hose pliers. Bleed clutch if necessary and check level in brake fluid reservoir. Use genuine Volvo DOT 4+ brake fluid when topping up.
Finishing
- Connect connector to brake fluid level sensor.
- Check that there are no leaks. Clean up any brake fluid spillage with lukewarm water and car-wash shampoo.
Replacing EBD pressure switch
Preparations
Clean around EBD pressure sensor connection to master cylinder.
Put rags under the EBD pressure sensor to protect painted surfaces against brake fluid spillage.
Get a drain bottle and hose to collect brake fluid in.
Removing EBD pressure sensor
Ignition off.
Jack front end of car up.
- Disconnect connector from EBD pressure sensor.
Remove:
- Protective cap from bleed nipple by LH front wheel.
- Connect hose to drain bottle.
- Open bleed nipple, depress brake pedal and hold it down or lock it in that position.
- Close bleed nipple.
- Remove EBD pressure sensor and plug connector so that no dirt enters the braking system.
Check EBD pressure sensor
The EBD pressure sensor comes with different seals between it and the master cylinder:
- O-ring
- Captive washer
- Conical seal
- Check that there is no dirt in the EBD pressure sensor connector.
Installing new EBD pressure sensor
- Install EBD pressure sensor. Tighten to 15 Nm (10.3 ft. lbs.).
- Connect connector to EBD pressure sensor. Release brake pedal. Top up with new brake fluid in the reservoir if required and bleed as necessary (See Bleeding brakes with bleeding unit. The EBD pressure sensor is located in the primary circuit, so only the primary circuit needs bleeding.
Finishing
- Connect connector to brake fluid level sensor.
- Check that there are no leaks. Clean up any brake fluid spillage with lukewarm water and car-wash shampoo.
Replacing the master cylinder
Preparations
Clean around brake fluid reservoir cap, by pipe connections, and, if necessary, by hose connection between reservoir and master cylinder to prevent dirt entering braking system.
Caution: Release non-return valve in air hydraulic brake power assist unit (brake servo) or pump brake pedal until it goes hard to avoid any vacuum remaining when undoing the master cylinder. Otherwise, there is a risk that the O-ring acting as a seal will be sucked into the servo and disappear.
Put rags under master cylinder to prevent brake fluid spillage on paintwork surfaces.
Note: Do not open the master cylinder under any circumstances. It takes special equipment and facilities to reassemble.
Removing master cylinder
Ignition off.
Remove:
- Brake fluid reservoir as per Brake fluid reservoirs replacement and cleaning. Brake fluid reservoir, replacement and cleaning.
Disconnect:
- Connector to EBD sensor from master cylinder.
- Brake pipe from master cylinder.
Plug brake pipe to prevent dirt entering braking system.
Remove:
- Mounting nuts.
- Master cylinder.
Installation, master cylinder.
Check:
- That there is no dirt in the master cylinder connections and that the packing box is intact.
Install:
- Master cylinder and EBD pressure sensor. Use new nuts. Tighten to 25 Nm (18.4 ft. lbs.).
Remove:
- Plugs from brake pipe and connect brake pipe. Tighten to 14 Nm (10.3 ft. lbs.).
Connect:
- Connector to EBD sensor.
- Brake fluid reservoir, as per Brake fluid reservoir, replacement and cleaning Brake fluid reservoir, replacement and cleaning.
Finishing
- Bleed braking system as per Bleeding brakes with bleeding unit. Bleeding brakes. Then continue as per instructions below.
- Bleed clutch on cars with manual transmission.
Clean off any brake fluid spillages with lukewarm water and car-wash shampoo.
Pressure-testing the braking system
Once the system has been bled, it must be pressure-tested.
Depress the brake pedal as if braking sharply, nearly enough to lock the wheels, for 30 seconds.
Check if there is any brake fluid leaking from the master cylinder.
Bleeding brakes with a bleeding unit
Note: Bleeding braking systems with ABS takes longer than bleeding conventional braking systems.
Guidelines for bleeding
When overhauling or replacing brake calipers, it is usually enough to bleed the brake pipe concerned as below. One condition is that the brake pedal must be depressed while working, so that the braking system is not drained of brake fluid. If the braking system has been drained, partly or completely, the complete braking system should be bled using the bleeding unit.
Note: Use only Volvo original brake fluid marked DOT 4+. Never re-use brake fluid. Always keep brake fluid in its original packing, well sealed.
Preparations
Ignition off.
Jack car up.
Clean filler cap on brake fluid reservoir and the surrounding area.
Remove:
- Filler cap.
Set bleeding unit to 0.2 - 0.3 MPa (29 - 42.7 psi).
Connecting bleeding unit
- Connect bleeding unit to brake fluid reservoir.
Follow manufacturers' instructions for connecting and using bleeding unit.
- Depress brake pedal a few times to expel any air bubbles from the master cylinder.
Note: Repeat this step between bleeding each brake caliper.
Bleeding LH front wheel
Remove:
- Protective cap from bleed nipple and connect hose from drain bottle.
Open bleed nipple and close it again once no further air bubbles can be seen in the escaping fluid.
Tighten bleed nipple.
Remove:
- Hose from bleed nipple and re-install protective cap.
Bleeding other wheels
Continue bleeding as per (LK4)-(LK5) in the following order:
- RH front wheel
- LH rear wheel
- RH rear wheel
Remove:
- Bleeding unit connector from brake fluid reservoir.
Check
- Check if there is any air left in the system by depressing the brake pedal as if braking sharply (a braking power equivalent to 200 N). With the engine off and the brake pedal depressed 3-4 times, the pedal travel should not exceed 40 mm (1.6 ins).
If pedal travel exceeds 40 mm (1.6 ins), bleed again and then re-check pedal travel.
Check that brake fluid level is not over the MAX mark.
Bleeding brake system without a bleeding unit
Note: Bleeding breaking system with ABS takes longer than bleeding conventional braking systems.
Guidelines for bleeding
When overhauling or replacing the brake caliper, mechanical bleeding in the usual way will normally be enough, but the brake pedal must be kept held down during the procedure, so that the braking system is not drained of brake fluid. If the braking system has been completely or partly drained, use the bleeding unit.
Note: Use only genuine Volvo brake fluid marked DOT 4+. Never reuse brake fluid. Always keep brake fluid in original pack and well sealed.
Preparations
Ignition off.
- Jack car up. Clean brake fluid reservoir filler cap and area around it.
Remove:
- Remove filler cap. Fill brake fluid reservoir completely.
Bleeding LH front wheel
Depress brake pedal a few times to remove any air bubbles in the master cylinder.
Note: This step must be carried out between bleeding each brake caliper concerned.
Note: Check continuously that there is enough brake fluid in the brake fluid reservoir when replacing brake fluid.
- Remove protective cap from bleed nipple and connect hose from collecting bottle.
- Open bleed nipple.
- Push brake pedal right down and hold it there for approximately 2 seconds before releasing it. Repeat this 20-30 times until there are no visible air bubbles in the drained fluid.
- Close bleed nipple.
- Depress brake pedal a few times.
- Open bleed nipple and close it when the break pedal is at the bottom. Repeat this 3-5 times.
- Remove hose and re-fit protective cap.
Bleeding other wheels
Continue bleeding as per in the following order:
- RH front Wheel.
- LH rear wheel.
- RH rear wheel.
Check
- Check if there is any air left in the system by depressing the brake pedal sharply (a braking power equivalent to 200 N). With the engine off and the brake pedal depressed 3-4 times, the pedal travel should not exceed 40 mm (1.6 ins).
If pedal travel is longer than 40 mm (1.6 ins) bleed again and then re-check pedal travel.
- Check that brake fluid level is not over the MAX mark.