Looking for a part number for the relay that powers the emergency secondary electric pump for the hydroboost. Also looking for the part number for the pressure switch. The relay is a 4 pin. 2 of the pins have wires soldered to them. The pressure switch is a 1 wire. Thanks

 

Check Rockauto - a quick scan shows that they have the Hydro-Max brake system parts, and some one wire brake switches - but you'll need to look at the photos to see if that's what you need. 1982 FORD F700 6.1L 370cid V8 Electrical-Switch & Relay Parts | RockAuto

 

Pressure switch is different than a brake switch. It senses if there is loss of power starring pressure through the master and kicks on the electric pump so you have brakes if the engine dies

 

Did you look at the site?
I said "brake switch" not the same as "brake light switch". At Rockauto their "brake switch" listing may be a "pressure switch", you need to look at the photos and part numbers.

I guess I'm not familiar with your setup. The hydro-boost systems I've seen have a pressurized chamber/canister to provide the emergency assist if engine dies. I'm not aware of an electric pump setup for the emergency assist (that would seem to be more problematic and would warrant a backup of its own ).

Your truck model is not covered in my Service Manual - maybe someone else has this info.

 

A truck that size may have a "brake light" on the dash if the asst. psi drops below a set psi and also sets off an alarm.
So that switch may be alarm/light brake switch.
Dave ----

 

You might go ask in the Large Truck forum and see what people there say.

https://www.ford-trucks.com/forums/forum232/

 

Look on these relays for Ford ID engineering numbers, post what you find.

Please ask further questions in the LARGE TRUCK forum, most members of this forum have pickups.