Inline Tube - 1970 F-85 W-31 Brake line install

1970 F-85 W-31
The most common brakes in the the late 60's and early 70's was power drum. Since disc brakes was new and you had to pay for the option most people stuck with what they new - drum brakes. As performance took over we all discovered if we drive fast we have to stop fast and so many performance cars were equipped with disc brakes. Performance was gained with bigger cams and this reduced vacuum and made power brake boosters not very functional so brakes was a direct relation to performance. This Oldsmobile F85 W31 has manual front disc brakes and rear drums. Now we jump 35 years and have a car that was restored in the late 80's before all the reproduction parts of today were available. This means the original lines, clamps, hoses, and valves are all the originals. The lines have been on and off, bent and unbent and put back on the car with deteriorated hardware and dry hoses. All this adds up to brake pressure loss. Bent and kinked or even rusty lines reduce flow. Dry rotted hoses could blow any day and old fluid can reduce brake power up to 30%. Over time brake fluid collects moisture, reducing effectiveness and rusting the inside of anything it is sitting in. Brake fluid should be changed every 5 to 6 years so this car should of had new fluid in it 6 times and we all know the last time we changed the fluid was never but we all remember topping it off. So it is time to get the fluid flowing at the right pressure.

Take a few pictures

Step 1. Take a few pictures for reference. Sometimes projects get started and life gets in the way and a day turns into a month and suddenly things are not as clear as they used to be. Also remember nothing takes 10 minutes. This brake job took professionals that work on these cars every day four hours. We used a lift and had all the correct tools for the job which makes this kind of job go faster than working on the driveway.

Plan ahead and order some parts

Step 2. It is hard to know everything you will need for the job but try to plan ahead. A few bucks spent ahead of time will save you many trips to the store or days if you have to mail order special parts. These cars are 35+ years old running to the local auto parts store is not an option anymore. Inline tube has everything for brake systems of any common car. We stock the brake lines and any other piece you will need for the job. For this job we have the brake lines, brake hoses, brake line clip set, master cylinder, frame distribution block, disc brake hold off valve, frame hose brackets, banjo bolts, dust covers and even the bleeder caps. Another great item that Inline tube carries is the factory assembly manual. This book shows all the routing and pictures the assembly of every piece. You can look up line routings, clip locations, and make sure no modifications have been made to your car over the years.

Start the disassembly

Step 3. We have started by loosening the master cylinder and the valve from the firewall. We have taken our line wrench and slightly loosened all the lines at the master and the valve. Only loosen but not enough to leak fluid. Remember the fluid will eat the paint so do not expose painted areas to fluid. We only slightly loosen so we can see where we are going to have problems with rusty lines or fittings that do not want to loosen up. If we tear into the project we may not be able to go back so take it slow at first this will save time in the end. Now we are ready to take the wheels off and proceed.

On to the wheels

Step 4. The wheels are off and everything is now loose at the caliper, brake hose and the brake line. Leave the brake hose in the frame bracket until you loosen the tube nut off the line. This will prevent the line and hose from just twisting around. Always use a line wrench on tube fittings. It has more sides so it will help prevent a rounded off nut. If you have a frozen nut that is beginning to round off STOP. Try tightening the nut first or with the master cap off heat up the fitting and if none of this works be prepared to get the vise grips out or cut the line at the fitting.

Under the car

Step 5. Now under the car we continue to loosen the lines on the valve and unclip the lines as we make our way to the back of the car. The valve is bolted to the car and the long bracket will want to twist the valve so a large wrench may be put on the valve body to keep it ridged. When taking clips off mark the holes they came from. There are many unused holes on the frame and it is easy to be confused on which hole the clip came from once they are all out laying on the ground.

At the rear of the car

Step 6. It is time to remove the rear axle lines and center hose. The axle lines are held to the axle by the metal welded on tabs that fold over to pinch the line against the axle housing. The rear hose is bolted to the axle housing and it is easier to loosen the lines before the block. The hose is held in with a u clip that can be removed with a pair of pliers by getting hold of the tab and twisting.

Now remove all parts

Step 7. Now that everything is loose it will only take minutes to remove it all from the car. It is important to save all the parts at this point.

Compare all parts

Step 8. Now it is time to compare all the old parts to the new parts to see if they all match up. It is hard to compare parts that are all cut up or twisted all out of shape that is why you do not want to rip them off the car. Since there were many manufactures making the original parts for the assembly line you may see minor differences. If something is wrong or does not match up you can now take a digital picture and email to the manufacture to show the problem. Email has been an enormous help in sorting out installation errors in the past few years. So save those old parts until the job is done, then you can throw them away or try your luck on ebay.

Bench bleed the components

Step 9. Brand new components have no fluid in them and if installed dry make bleeding brakes a long drawn out process. To bench bleed the master fill with fluid and use a bleeder kit that should be included with the new master. This will take out all the air after 10-15 full strokes. The car pedal only moves a small amount of fluid at a time causing this to take much longer on the car. Also at the bench you can watch the fluid to see when all the air is out. If you are replacing calipers or wheel cylinder make sure to push the piston in the full amount. This will reduce the amount of air in the system making bleeding much faster.

Leave it loose

Step 10. Now it is time to start putting parts back on the car. Fit all the lines back in place just like when you took them off. Start the fitting in the holes get the brackets and the valve in place. DO NOT TIGHTEN any of the parts. Fit them in place and get all the bolts started but again do not tighten anything. By leaving thing loose it gives you more wiggle room to get fitting started and get alignments of the seats to the components.

Tighten it up

Step 11. Now that all the bolts are started it is a matter of going around and tightening up the system. If you are using used components don't be surprised if you have a leaker. The new tubing must form a seat in the used component which already has a seat from the former line so it must be tightened beyond the old seat. If the line is tightened and a leak occurs loosen and tighten several time to form a new seat. Cranking the line down will only round off the nut and not stop the leak, a seat must be formed.

Adjust the line

Step 11. Never use Teflon tape on brake line fittings. This tape is designed for tapered fitting or pipe fittings. If used on brake line fittings it will not stop the leak because the threads do not seal the fitting the union of the flare to the seat is what seals the system. The tape may stop the leak at the threads but it will soon move to where the tube goes through the fitting. If the angle of the line seem to be slightly off and you can not get the fitting started in the hole first loosen the hose to get some wiggle room if this does not work slight adjusting of the line may be required. With an open end wrench put the wrench on the hex of the fitting and use the wrench to bend the end into place. It is common when installing lines on cars that are all together to have to make slight adjustments. It is hard to work around the other components and mechanicals that may be in the way or close to the lines. When you car was built at the factory the lines were one of the first items installed when nothing was in the way.

Fill her up

Step 12. Now that everything is tight it is time to fill the master and bleed the brakes. Fill the master and before pumping the brakes look for leaks. Now pump the brakes and again get out and look for leaks. If you are lucky enough not to have any leaks proceed with the bleeding. If you have a leak pin point it and inspect to make sure the line is straight and the fitting is in straight and proceed to loosen and tighten several times to form a seat in the brass of the component.

Finish the bleeding

Step 13. For bleeding the brakes you will need at least 2 people clear plastic tubing and a waste jar. We have always found the best way to bleed the brakes is to fill the master and start at the furthest wheel first which is the passenger side rear. Crack the bleeder and push the pedal down several time until fluid appears at your clear rubber tube. The clear tubing allows you to see the air bubbles. Then repeat this for the driver rear then the passenger front and finally the driver front. At this point you will have a pedal but a weak one. Now go back to the wheel you started at an open the bleeder and the other person will slowly press the pedal several times pushing the fluid through the system when steady air free stream is achieved after a few pedal depressions close the bleeder and move on to the next wheel. Now you will have a 70% pedal. Next round will be a bit different, with the bleeder closed pump up the brakes and hold when the bleeder is opened depress the pedal to the floor holding until the bleeder is tightened. Repeat until there is no air bubbles then proceed to the next wheel. Make sure to check the master cylinder fluid level frequently because if you run out of fluid you will have to start the entire process over again.

Consult your mechanic
This page is intended for use as a basic guide to help install new brake and fuel lines. If you are unsure about any part of the installation procedure, please consult a certified, professional mechanic for assistance. Inline Tube assumes no responsibility or liability for improperly installed lines.

Quick Tip: Line Installation

Line Installation - Refer to the disassembly photos. There are many holes in the frame and it is impossible to remember which are the correct holes for line clip mounting. If you do not have photos, many parts retailers sell factory assembly manuals that show in detail where each of the clips are located in the frame. The manuals are available for cars such as Camaro, Chevelle, Nova and Corvette through Inline Tube.

Sources:

Inline Tube - Brake & Fuel Lines

15066 Technology Drive
Shelby Twp, MI 48315
(586) 532-1338

www.Inlinetube.com