Astro Van M L4-151 2.5L (1985)
Technical Service Bulletin # 873015
Date: 881101
Brakes - Enhanced Braking Performance
Number:
87-301-5
Section:
5
Date:
NOV., 1988
Subject:
BRAKE PERFORMANCE
Model and Year:
1985-87 M-VANS
TO:
ALL CHEVROLET DEALERS
This bulletin cancels and replaces Chevrolet Dealer Service Bulletin 86-T-219 (Section 5) dated February, 1987, and includes additional diagnostic
information. All copies of 86-T-219 should be discarded.
Astro vans are designed to carry varying loads, and therefore, they are equipped with brakes that are capable of good stopping performance under a
variety of conditions. Some customers who operate their Astro vans heavily loaded most of the time may prefer additional rear braking. If so, the
following procedure is an acceptable method of increasing rear braking on 1985, 1986 and some 1987 Astro vans. It will result in a higher rate of
deceleration at wheel slide and shorter stopping distances in a heavily loaded condition. The customer should be informed that there will be an increase
in rear brake performance and the potential for rear wheel skid in unladen applications.
Astro vans, in both their original condition or as changed by this bulletin, meet all the stopping requirements of Federal Motor Vehicle Safety Standard
105 for Light Duty Trucks.
Service Procedure 1985-1986 Models
Service Procedure
Note:
Care must be taken to prevent brake fluid from contacting any painted surface.
1985-1986 Models:
Always ensure that the brake system is operational after performing brake work and before returning the vehicle to the customer.
Steps A, B, and D involve all subject vehicles. Step C is engine dependent.
FIGURE 1 - COMBINATION VALVE
A.
Replacement of the combination valve, Figure 1.
1.
Disconnect negative battery cable.
2.
Disconnect the four brake lines at the combination valve.
3.
Disconnect electrical harness at the combination valve.
4.
Disconnect combination valve at bracket on the brake booster and discard valve.
5.
Install new combination valve (P/N 15571205).
6.
Reverse above procedure for reinstallation and tighten bracket nuts to 50 N-m (37 ft.lbs.).
7.
Reinstall brake lines and torque nuts to 25 N-m (18 ft.lbs.).
