First of all, when you want someone's attention, read his/her message and reply from there. Do not reply to yourself!

I am sending youa write-up (incomplete) that I did on all tubings/hoses for '85 760TI. My car is very similar to yours.

Based on the information you gave and that the OD of this hose is 0.5 cm, the only other choice is either the cruise control or the ACC. I don't have my car with me here. I hope the following may be helpful in eliminating at least.

Volvo Hoses and Tubing Systems

Purpose: The purpose is to buy the available parts, in this case, hoses and tubings, from auto parts stores, hardware stores or industrial supply outlets instead or from Volvo dealers.

General Rules:

1. All hoses and tubing are identified by their ID (internal diameter).

2. It is permissible and sometimes advisable to have a longer hose than a shorter hose.

3. It is permissible to use a fuel injection (high pressure) hose for low pressure fuel, oil, vapor, coolant, vacuum applications.

4. It is permissible to use fuel hose for oil, vapor, coolant and vacuum applications.

5. Heater hose and vacuum hose must not be used for fuel under all conditions.

Note:

Top is ACC

Middle is turbo control

Bottom is turbo gauge

Front: fuel

Rear: vacuum booster

For the Volvo 1985 760 series with turbo intercooler, as well as any other model, there are basically three systems:

· Cooling system

· Fuel delivery system

· Vacuum system

· Power steering Fluid system

· Refrigerant system

· Turbo system

· Cruise control system

· Braking fluid system

· Oil Cooler system

· Windshield fluid system

Each system has different fluids under different conditions. Hence the requirements for the hoses or tubings are different.

1. Cooling system. A mixture of coolant/water mixture circulates from the engine to the radiator and the heater (on demand). The coolant is maintained under pressure, so that its boiling point is raised to above 212 degree F.

a. Upper radiator hose. From thermostat housing to top of the radiator. OEM or after market. Pre-mould. Available from any auto parts store.

b. Lower radiator hose. From the bottom of the radiator to the water pump. OEM or after market. Pre-mould. Available from any auto parts store.

c. Radiator filler hose. From bottom of coolant overflow or expansion tank to middle of radiator. Volvo used a weird hose for this purpose. The nozzle at the bottom of this plastic tank is one size larger (1/2” or 5/8”) than the nozzle at the radiator (3/8”)! This is ridiculous. Consequently, any replacement hose has to be purchased from Volvo. There is an easy modification so that one can use a 3/8” hose for this purpose. Buy a brass connector with ¼” male NPT and 3/8” barb (#1). Also buy a 3/8” male NPT by ¼” female NPT brass reducer (#2). Saw away the male 3/8” portion of the reducer (#2). What is left is a nut with ¼” female NPT (about 1/8” thick). Cut away the bottom nozzle at the plastic tank (Before you actually cut this nozzle away, go through the following exercise mentally. Once you cut it, the process is irreversible.) Drill a hole through the cut, big enough for the first brass connector (#1) to go in. Find a thin washer with a hole that is just big enough for the ¼” male NPT (#1) to go in. You may have to drill a washer with about 3/4” OD to size. Insert the ¼” male NPT by 3/8” barb (#1) with the ¼” male NPT through the washer and into the plastic tank. Put the ¼” female NPT nut that you just made into the inside of the tank and rotate it onto the ¼” male NPT. Don’t forget to use some silicone sealant for perfect seal. Use a socket wrench and an open-end wrench and tighten the two pieces. Now, you have just modified the tank with a 3/8” barb outlet, which is the same size as the nozzle on the radiator. Because there is a swaging at the nozzle at the radiator, 3/8” (0.38”) ID hose will fit perfectly. I cut a piece of washing machine hose. It fits perfectly. Length = 2’. (After a year of service, it is still in good shape.) Alternate hose: fuel hose with same ID.

d. Radiator venting hose. From top of radiator to top of plastic overflow tank. The size is 5/16” ID. Heater hose seldom comes in this size. Use fuel hose. Length = 3 ft. The nozzle at the plastic tank may be slightly too large for the hose. Use sand paper and sand it down a little.

e. From engine via a valve to nozzle on firewall. The size is 5/8” ID heater hose. With my ‘83 245, I was able to use a generic pre-mould heater hose. I believe it was a Goodyear product with the part number 63036. It looked like the Greek alphabet sigma, with each side about 3”. Cost in1997 was $4.70. Alternate: use a pre-mould angle hose that is about 4” by 12” (to be verified). Go to any auto parts store and ask them to find you a hose with the above size. See below.

f. From nozzle on firewall to water pump inlet. This is the return of water back to engine. 5/8” ID heater hose. (Same as above, except the part number was 63812. Cost in 1997 was $6.70. This was a 4” by 12” angle hose.)

g. From firewall to heater core. Size is 5/8” ID. (I did it on 245. 700 should be the same.)

h. From heater core to firewall. Size is 5/8” ID. (I did it on 245. 700 should be the same.)

2. Fuel delivery system

Fuel pump to fuel filter. ¼” ID fuel injection hose. 3” long.

Fuel filter inlet. 19 mm bolt. Fuel filter body 24 mm.

Fuel filter outlet. Fuel filter body 22 mm. 18 mm bolt.

Fuel filter to Fuel injection rail.

Fuel pressure regulator to tank hose.

3. Power Steering System

a. From fluid reservoir to fluid pump inlet. Size 5/8” ID. There is no pressure involved. It is just a filler pipe. I used regular fuel tubing cut to length. Length = 5 ft.

b. Discharge from steering unit to reservoir. The aluminum tubing is 10 mm OD. Hence tubing used is 3/8” ID. Type, fuel hose. Again, the pressure is low. Fuel hose should be sufficient. Length = 3 ft. (I used a high pressure fuel injection hose.)

4. ACC System

3/8” ID hose.

5. Cruise Control. All the connectors have 0.28” OD (?). Size of hose is 7/32” (0.22”). I rearranged the layout a little bit. At the vacuum pump on the left fender, there is a rubber tee ( x x ID), which connects to the two inlets. This one stays. I made an reducer by cutting of the pipe portion and soldered two barbed connectors end to end. This becomes a by reducer (male, male). This is inserted into the rubber tee.

6. PCV.

a. From oil trap to plastic adapter. Use fuel hose 9/16” ID. Length = 6”.

b. Plastic adapter 5/8” by 5/8” by 0.2”

c. From plastic adapter to turbo suction hose. Use 9/16” ID fuel hose. Length = 20”~22”.

d. From plastic adapter to throttle. Use 3/16” ID vacuum tubing (or any type of tubing). Length = 4”.

e. The tubing/pipe adapter is 3/16” by 1/8” male NPT.

7. Fuel pressure control. Size: 3/16” ID. Length = 12”. From front of the throttle house to pressure regulator.

8. Power Brake Booster Hose. 3/8” angle plastic adapter 3/8” barb by unknown connection on the booster housing. The metal adapter on the throttle is 3/8” barb by ¼” NPT male. Use 3/8” ID fuel hose. Length = 18”. (7/99)

8. Turbo gauge. Tubing size: 3/16” ID. From the throttle housing, the adapter is 3/16” barb by 1/8” male NPT. The tubing goes through the firewall to behind the dash. Length = 4’-6”. The end is attached to a tee. Two pieces 7” and 13”. The short one is connected to a switch at the gas pedal, and the long one is connected to the turbo gauge via an angle plastic adapter behind the instrument panel.

9. Windshield spray system. Fluid: water with additive such as alcohol. Pressure: low