Date:         Sat, 17 Jul 2021 13:51:47 +0000
Reply-To:     Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject:      Rear brakes resend due to reply getting blocked.
Content-Type: text/plain; charset="us-ascii"

When it comes to the rear brakes there often seems to be some difficulty them right. Here are some considerations to get them to work.

Wheel cylinders, these are are a weak link and probably half the rear brakes I do are do to the cylinders leaking. If they have been in their long enough to wear out the shoes or drums than they should be replaced. Pull the outer boots back, if there is fluid there they are starting the leak. They travel over some area and once disturbed as part of the shoe replacement a future leak is eminent. Make sure to get the correct ones. You need the ATE with the spring that pushes the piston out against the shoe. Without this spring suck back will give you a pedal that will often need that extra pump.



Shoes, Almost all the shoes available have linings that are not the correct thickness and the curve of the shoe follows the old busses that had the adjusters on the bottom. These do make good contact especially when new and only a small part of the friction surface touches the drum. They need to be shimmed out at the bottom. The lower shoe rest are removable, may require some heat and 14mm shims will fit. McMaster Carr has 1 and .5 mm shims in Stainless. 3mm each shoe is fairly normal. I have done some up to 4.5mm. Also measure the drum diameter. They do wear and the wear limit is 9.980". The drums also flex especially when the shoes have a limited contact area. A tool like this is real handy for checking the drums and setting the initial adjustment-shims.

https://www.amazon.com/Westward-1EKA5-Brake-Resetting-Gauge/dp/B001GIUCSK/ref=sr_1_4?crid=36H2WVZZBZP4Z&dchild=1&keywords=brake+drum+measurement+tool&qid=1626528272&sprefix=brake+drum+measure%2Caps%2C143&sr=8-4



Assembly, It is amazing how many come to me with the brakes assembled or the handbrake cable adjusted wrong. The top springs need to be installed with the hooks facing up. The adjuster rod gets installed wit the long side of the rear fork behind the lever resting on the bottom of the shoe slot. Assemble without connecting handbrake or installing the adjuster level spring. Adjust the rod to take up the slack but not push the shoes out yet. Now install the handbrake cable and adjust so that the lever almost touches the adjusting rod. It is important that when the handbrake is released it does not put any pressure on the rod. If it does the self-adjuster will not work.  Also make sure that adjuster turns freely. No grease or never seize. The only way to properly adjust the handbrake cable is with the drum off so you can see the lever gap. Put the adjusting lever spring back on. When set up correctly you can hear the lever click as it turns the wheel when the foot brakes are applied.



Bleeding, Brake fluid should be renewed every 2 or 3 years. It absorbs moisture which lowers the boiling point and creates corrosion in the system. Corrosion on the cylinders causes the rear cylinders to leak and the calipers to get stuck. It also rusts the brake lines from the inside out. It can also damage the master cylinder and the rear brake pressure regulator. Frequent bleeding also help prevent the bleeder screws from rusting in place. For vacuum bleeding some grease on the bleeder thread will help avoid air getting sucked in there. For single person brake bleeding one of these bleeder hoses makes things easier.



https://www.amazon.com/vbaxy-Bleeder-Bleeding-Motorcycle-Clutch/dp/B08H4ZJBJM/ref=sr_1_2_sspa?crid=1PNXTYDA8RRPO&dchild=1&keywords=brake+bleeder+hose&qid=1626529396&sprefix=brake+blleder%2Caps%2C163&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzVlNTVDBRRzhDTEtOJmVuY3J5cHRlZElkPUEwMzMzMDc5MVI0STdGWVVYTDNDWSZlbmNyeXB0ZWRBZElkPUEwMDY0NzAyM1JYSTUzNVowWVJITSZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=



Shoe seating, new shoes will need to seat and wear into the drum. Drive a bit and then pull the drums to see the wear pattern if they don't improve with some miles. With old drums that rust ridge is also going to effect adjustment.



Hope this helps,

Dennis