1987 740 Turbo Vacum hose routing

Salomons Driveway · Post by **Salomons Driveway** » 24 Jan 2015, 09:24

Would anyone know of a vaccum hose routing diagram for the 740 Turbo with B230FT, 4 cylinder engine?
After removing and rebuilding the engine, I am not sure whether the two hoses that come out of the firewall on the driver's side of the engine compartment connect to the manifold or the vacum pump. There is also a 4mm vaccum line comming off the intake manifold between the engine and throttle body with no obvious place to go.
The other 3 lines comming off the throttle body go to the Turbo, PCV and a large diameter line running under the radiator.[740 Int Man Vaccum lines.jpg]

93Regina · Post by **93Regina** » 24 Jan 2015, 11:57

Salomons Driveway wrote:Would anyone know

Vacuum Hose Replacement. To replace your rubber vacuum hoses (not the hard tubes), buy the following quantities (1 inch=2.54 cm):

Salomons Driveway · Post by **Salomons Driveway** » 24 Jan 2015, 12:13

Great link for hose sizing. Unfortunately, my hoses seem good, they just need to be connected or capped off because the resulting vaccum leak keeps the engine from starting.

93Regina · Post by **93Regina** » 25 Jan 2015, 06:03

Salomons Driveway wrote:Great link for hose sizing.

In earlier years, before 1975, Volvo's Green Manuals showed vacuum circuits; afterwards, most all, if not all, OEMs placed a sticker in engine compartment for emission related vacuum circuit.

A parts catalog should/may show what you are looking for, but you need to find a part number for something in that vacuum circuit, then Google it, and find OEM part catalog.

Otherwise, use your digital camera before taking apart or removing engine, etc; this is my method, and it works 100%.

Salomons Driveway · Post by **Salomons Driveway** » 04 Feb 2015, 09:25

The mystery vaccum line off the intake manifold went to the dash instrument turbo gauge.
Finally, the car starts and drives again!