Posted by Ben on April 13, 03 at 21:32:08:
In Reply to: Hydroboost unit is drooling. posted by Allen on April 13, 03 at 19:26:33:
Exactly like replacing a vacuum booster.
Four nuts hold the hydrobooster onto the fire wall. Nuts are accessable from inside. Think they are 5/16" hex nuts and will need deep socket. Only wiring is switch that is on brake pedal/hydrobooster rod connection. $1 special washer holds that together. Usually have to break the washer to tear apart, but can be taken apart if you look closely how it's snapped into a grove on the shaft. Swith then rotates upwards and off the hydrobooster rod, which then can be removed from the brake pedal arm's hole. Don't have to remove the wires from the switch, just move it out of the way.
Then remove the two nuts holding the MC to the hydrobooster, then the 4 bolts inside the firewall. The hydrualic lines to the MC do not have to be disconnected if you loosen the ABS controller assembly and it all moves foward enough (you'll see why).
There are three lines and easy to see how they route, as there's a plastic holder for them underneath.
Make sure you check the hydrobooster rod for brake pedal, as went through several and finally found out that they come in differing lengths 'cuz the 1 ton and larger have different lengths, but use same hydrobooster. Best to confirm that they have more than one in stock, take your's apart and compare on the counter before leaving.
Also double check the hydrobooster after installed. Went through about 4 that all leaked at same junction. Parts house dropped that vendor 'cuz of my experience. Find that not many know anything about hydrobooster and you'll quickly become an expert. Find a parts place that does 3/4 ton & 1 ton trucks, lots of them. Of the two NAPA stores, one great, other worthless. Great one did lots of 3/4 ton & 1 ton truck business. $179 plus $75 core charge. Becareful, there are some that do NOT have that plate with the 4 hardened studs and is NOT what you want, get the one with the hardened plate & hardened studs.
Bleed/flush the steering/hydrobooster system with several quarts of new fluid. Used to use Valvoline Synthetic, but am in process of switching to regular Valvoline. Hearing on other boards that Valvoline synthetic may cause leaks...and don't want to go through this again. Flush every year or every 2 max time peroid between...why did they put external cooler for this? Must really be tough duty working both steering & brakes.
NOTE that the hydraulic fluid *DESOLVES* the undercoating on the frame and you will need to recoat. I like Amsoil HD Metal Protectorant.
PS...back ach working upside down, face down, face up, etc. Ended up making board that let me put whole body same level as Sub's floor so that if felt like laying on the ground.