Power Brake Units - BENDIX HYDROBOOST: Overhaul: Reassembly
- Be sure that all parts are absolutely clean. Lubricate all seals and metal friction points with power steering fluid.
- On Chevrolet and GMC models, install tube seat as shown in Fig 2. On Dodge and Plymouth models, position tube seats in booster ports and screw a spare tube nut into each port to seal tube seat. Remove spare nuts and ensure that ports are free from burrs or shavings.
- Install "O" ring, spool valve plug and retaining ring. Coat piston seal and bore with clean power steering fluid and place seal in bore. Lip of seal must be facing away from master cylinder mounting flange. Lubricate input rod end, new input rod seals and seal installer tool (see tool chart for number) with clean power steering fluid.
- Slide seals on tool with lip of cups toward open end of tool. See Fig 1. Slide tool over input rod end and down to second groove. Then slide forward seal off tool and into groove. Assemble other seal in first groove. Make sure both seals are seated.NOTE: Chevrolet and GMC diesel models use only 1 seal on input rod.
- Lubricate piston and piston installation tool (see tool chart for tool number) with clean power steering fluid. Hold the large end of the tool against the piston and slide the tool and piston into the piston bore and through the piston seal. Remove tool. Install return hose "O" ring fitting. If accumulator valve was removed, install new seat in valve bore by installing 2 function valve, which forces seat to bottom in bore.
- If removed, insert new dump valve over the 2 function valve, making certain the dump valve plunger is held in place until installation is complete. Insert spool valve spring and valve assembly into bore. Extend power piston lever to accept sleeve on spool valve, then slide lever pins into slot in sleeve.
- Install new seal in groove in housing cover, then join booster housing and cover and secure with 5 screws. Install output rod, spring and new spring retainer. Install new baffle and spring retainer by pushing in on it with a 7/8" socket.
- Lubricate accumulator seal with clean power steering fluid and install seal and accumulator in housing. Place retaining ring over accumulator. Place tool (see tool chart for tool number) over accumulator. Using "C" clamp, compress accumulator straight in. Snap retaining ring into the housing groove, and remove "C" clamp and tool.
- Position mounting on booster. Tab on inside diameter of large hole in bracket should fit into slot in threaded portion of booster hub. Install new bracket nut with staking groove outward on the threaded hub of booster. Using deep socket tool (see tool chart for tool number) and a torque wrench, tighten nut to 110 ft. lbs.
- Using a hammer and punch, stake the nut in place. Assembly boot (if used) on pedal rod. Assemble new grommet in groove near end of pedal rod. Moisten grommet with water and insert grommet end of the pedal rod into the input rod end of the booster housing. Push on end of pedal rod to seat grommet. Slide the boot on the pedal rod and assemble the large end of the boot onto the hub of the power section.
TOOL NUMBER CHART
| Application | GM Number | Chry. Number | ||
|---|---|---|---|---|
| Retainer Shearer | J-24569 | C-4396 | ||
| Retaining Cap Tool | J-26889 | |||
| Input Rod Seal Tool | C-4394 | |||
| Rear Drum Models | ||||
| Gasoline | J-24553 | |||
| Diesel | J-28485 | |||
| Rear Disc Models | J-28497 | |||
| Piston Installation Tool | C-4393 | |||
| Diesel Models | J-25083 | |||
| All Others | J-24551 | |||
| Special Deep Socket | J-24554 | C-4395 | ||
| Tube Seat Installer | J-6217 | |||
TIGHTENING SPECIFICATIONS
| Application | Ft. Lbs. |
|---|---|
| Booster Housing | 20 |
| Mounting Bracket Nut | 110 |
| Booster Brackets | 25 |