Freshly tuned carburetors, proper running adjustments,
an oil and filter change; these are just the start of a successful
driving season. Making sure that your car will stop is probably the
most important part of the spring maintenance routine. This year, why not
give your car a safety check?
1.
Excessive pedal travel and/or excessive handbrake movement indicates an
overdue adjustment or the need for new pads or shoes.
2. Sticky wheel cylinder pistons or incorrect master cylinder push rod adjustment will result in a 'dead' feeling pedal. Air in the system is the most common cause of 'spongy' pedal. These are the most common of storage-related brake problems.
3. An obvious and serious brake problem is indicated by the abnormal loss of fluid once the car is put in service. Do not just keep on filling the reservoir; clean and tighten the brake fluid connections. Look for fluid seeping out of the cylinder seals. Pay special attention to the master cylinder. If wheel cylinders leak into the brake assembly, the fluid quickly ruins the shoes.
4. Leaky rear oil seals are also a prime source of brake contamination. Often, both leaky wheel cylinders and oil seals rob your stopping safety. Determine the culprit and correct the problem.
5. Shoes that have been soaked with brake fluid and oil may sometimes be reclaimed with a proprietary brake cleaner, but it is usually necessary to replace them, as rear axle oil will soften the friction material, greatly reducing its efficiency and safety.
6. As brake fluid is susceptible to water contamination, it is essential to bleed the brake system once a year. Worn seals will allow air to enter the system without a sign of fluid leak. The need for repeated bleedings is a sure indicator of this fault.
N.B. Absolute cleanliness is essential when servicing brake systems. Be sure that the master cylinder top is clean before it is opened, so no dirt or grit enters the system. Small rubber caps (Moss 031-300) are available to cover bleed screws, and are an inexpensive and convenient way to keep dirt out of the bleeders. Wash the backplates and any other gritty areas before anything is disassembled for service. Remove the drums and clean the parts with brake cleaner or soap and hot water. Do not use an air blast to clean brake assemblies. The asbestos particles are a proven carcinogen. Do not handle the clean parts with dirty hands.
7. Carefully inspect the cylinder bores. Units having rust pitting, score marks, and 'rings' left by corrosion must be replaced. Internal parts must also be in good order. Disc brake pistons that are rusted or corroded will not hold a seal, nor will plungers and pistons that are scored or worn on one side.
8. Examine the rubber hydraulic hoses. The connections to the metal piping are commonly covered in grease. This area should be kept clean so any indication of cracking or swelling can be observed. An uncommon problem with rubber hydraulic hoses occurs when the inside of the hose swells and cuts off the fluid flow. No problem is apparent on the outside. If you are bleeding the system and no air or fluid passes from the cylinder in question, consider removing the rubber hose for close inspection.
9.
It is preferable to visually inspect front drum brake systems where two
cylinders are used. Back off the adjusters to permit the removal of the
drum. Get a helper to push the pedal gently. Observe the action of the
cylinders' pistons - only one cylinder may be working, while the other
may be stuck. That will stop the wheel, but not very well. If the cylinder
does not retract fully when pressure is released you can see right
away that it will have to be rebuilt.
Tech Tip: Stuck pistons can be forced from
cylinders by air pressure. Clean the cylinder; remove
corrosion in the exposed bore. Use an air nozzle
to force air into the cylinder, covering the open end with
a rag to prevent damage from flying pistons.
When rebuilding disc brake calipers, your shop manual or other service instructions probably recommend removal of the pistons by using pressure from the hydraulic system. This method is not only messy, but inhibits the work by allowing removal of only one piston at a time. It also forces you to work on the caliper under the confines of the fender while it is tethered to the chassis by the brake hose.
However, there is an alternative mechanical method which permits removal of both pistons at once, while allowing you to do the work off the car. Remove the caliper assembly from the car, disconnecting the hydraulic hose at the caliper. Determine the inside diameter of the caliper piston, then visit the hardware store and find a plumber's "test plug", or try the auto store for the rubber plug used to replace the steel expansion plug in a cylinder block core opening. Both are rubber sleeves with concave washers at each end and a center bolt used to compress and swell the rubber sleeve. Choose one of a diameter as close as possible to the piston bore.
Now cut a piece of 1/4" x 1" steel strap about 6" long and drill a hole in the center that will fit the bolt in the expansion plug. Install the strap on the center bolt with the nut finger tight and cut off the bolt flush with the nut.
Insert the plug in the piston bore, install the strap and tighten the nut securely to cause the plug to grip the inside of the bore. If the plug should prove too small to expand enough to grip the piston, securely wrap a few turns of rubber tape around it until it is large enough to grip as needed. Rubber tape is far better than plastic or electrical tape because it will expand with the plug, having good friction characteristics.
Once the plug is tight in the bore, grasp the caliper and tool assembly with both hands, placing the thumbs on the back of the opposite cylinder and the fingers around the strap. Squeezing the hands closed will extract the piston from the bore. Then repeat for the opposite side. Either this tool or a C-clamp can be used to install the pistons following the rework.
It
is a very common fault to find brake bleed nipples over-tightened
(sometimes to the point where they shear or crack the alloy casting). Girling
states that "a torque of 4 to 6 lb. ft. should be applied, which
is sufficient to lock the bleed screws up without damaging the orifices
of the ports. If the orifice has been enlarged and the tell-tale
black ring can be seen on the conical seating, then this is a sure sign
of over-tightening."
Brake Cylinder "C" Clip Installation Made Easy
There is easier way to install the large "C" clip that retains the rear wheel brake hydraulic cylinder of the in place. With the wheel and the brake drum off, you will see that the axle flange sits almost directly above the hole through which the slotted "neck" of the wheel cylinder is installed. Clamp a large vise grip wrench to the bottom of the axle flange with the head of the wrench pushing against the wheel cylinder (as shown), and you will now have your own two hands free to install the "C" clip.
The
concave side of the clip is positioned against the inner side of the brake
shoe backing plate. Insert one flanged end of the clip into the slot of
the wheel cylinder, followed by the middle flange. Use a flat screwdriver
and hammer to ensure that these first two flanges enter into the circular
slot of the wheel cylinder.
The screwdriver is then used to lift/pry the third flange
of the clip up and over the neck of the wheel cylinder to snap it into
the circular slot. Check that all three flanged areas of the clip are fully
within the circular slot, and voila, you have completed the job with no
damage to the "C" clip itself, and almost
faster than it takes to read this how-to-do-it.
The pre-June 1993 rear brakes require regular adjustment for wear.
(The post-1993 rear brakles are self-adjusting but please see the GoMoG note on them as well.)
The adjuster is found at the rear of each rear brake. It is a square post that can be turned
in each direction. It can be held in a brake adjuster tool or clamped in a small needle nose vice grip.
Each "notch" turned pushes the shoes closer or farther from the drum.
Raise the rear of the car off the ground. Place it on stands. Remove the rear wheels one at a time.
Turn the adjuster until you can no longer turn the drum. Now turn the other way once or twice, until you
can move the drum. A slight "scuff" is permissible, but no drag must be present. Now turn the other way once
or twice, until you can move the drum. Put the wheel back on and repeat for the other side.
Check the drum for concentricity if the adjusters must be backed off an
excessive amount. On twin cylinder systems, adjust each shoe in turn. It
is advisable to remove the brake drums at least once each year to inspect
the linings and drum surfaces.
Routing the Safety Brake Cable
All Morgan hand brake cables are the same length.
The cable is routed over the crossmember at the back of the transmission
then UNDER the left transmission mount leg then in between the body
of the transmission and the end of the mount ear. The cable should
then be more then long enough to reach the safety brake junction.
.
The brake shoes are pulled off by the shoe return springs
that are inside the brake drum when the hand brake is released. There
is no other return spring nor is one necessary.
There is supposed to be one cable clamp that holds the cable to the left battery floor as it comes out of the drive shaft tunnel and before it reaches the attachment on the rear axle. The cable passes over all the crossmembers.
One
of the less popular aspects of wire wheels is that they tend to go "out-of
tune" and need occasional straightening (or "truing"). This is caused by
the spokes stretching and by the spoke holes wearing, both of which result
in a change in spoke tension. This causes the rim to run out-of-round.
Consider that the weight of the car is suspended on the few spokes that are uppermost in each wheel and that they are constantly moving into and out of this weight-bearing position when the car is moving. Add side loads from cornering and you can understand the stresses that cause the spokes to stretch and move around.
A wheel which is tuned to run true may be kept this way by a monthly checking of spoke tension. Run a pencil around the spokes and note whether any make a sound which is markedly lower in pitch than the others. Tighten these "flat" ones with a Moss spoke wrench (#385-800) and you will maintain the wheel in a nice, round condition.
If your wheels have not been trued for some time, simply
tightening the "flat" spokes will not necessarily make them run true. You
might just tighten them permanently into their buckled condition! An old
wheel should be properly trued to eliminate radial and lateral run out
before being put on the monthly
maintenance program. see Tuning
Wire Wheels.
Dissolving Hardened Wire Wheel Grease
Because servicing them is a dirty job, wire wheels are perhaps the most neglected components on a British car. Many times I've bought or worked on a car and found it nearly impossible to remove one of the wheels! This is likely due to very hard, dried-up grease which essentially freezes the wheel on.
I've heard about many techniques for removing stuck wheels with torches and chisels, and even trying to drive around without the knock-offs installed to loosen the the wheel. Before resorting to such drastic measures, try using a can of carburetor cleaner to dissolve dried up grease. Jack the car up, remove the knock-offs and spray well up into the cavity between the wheel hub and the splined extension, The carb cleaner will dissolve hardened grease in short order.
Be sure to place a pan or tray under the wheel to catch the dissolved grease and carb cleaner. Let the carb cleaner soak in for a few minutes and repeat the process while wiggling the wheel around to help break up hardened grease.
There are a number of methods and theories on mounting wires wheels. This article will deal with them.
First and foremost, let's examine the goal and the dangers of not attaining it. Most wire wheels (and all those used on Morgans) mount the wheels on a splined post which interfaces with splines in the wheel's hub. The wheel is held on the splines by large thread nut called a spinner, where can have two or three ears or be a simple hexagon. They can be tightened in number of fashions which will discussed a bit further on. The recommended system is to make the snug in the air and then torque on the ground.
eMog Pub "When I had my 1956 TR3 I recall reading that the spinners wheels of the Rudge-Whitworth design are self-tightening due to the interaction of the tapered face on the hub with the tapered backside of the wheel. According to that author, one should be able to snug them down (not excessively) and drive off, ending up with spinners tighter after driving. Duncan"
I have run across that as well. It is the old debate between the tighten-only-til-snug and the bang-em-til-you're-blue-in-the-face crowds. Some manufacturers will tell you one way and others will tell you the opposite.
What IS definite is that there has been much misery over the years with Morgan knock-offs and, for that matter, other marques. The reason is simple, if there is ANY looseness, the splines on both the wheels and the hubs wear VERY quickly. If the spinners are supposed to "self-tighten", someone forgot to tell the spinners. With the Later Plus 8 and early Aero 8 alloy knockoffs, the situation became epidemic and the Factory had to send out super long spanners to the owners to install and remove them.
I have been a "banger" (smile) forever and my wheel/hub splines are great!
Tim Waller made the debate more detailed some years ago
on eMog. He noted that Ferrari recommended 300 lbft. of torque for knockoffs.
After testing mine, I found them to be 250. That can ONLY be
achieved with rigorous metal on metal banging with a hammer.
US
SOURCE I
or a long bar for leverage and torque.
US
SOURCE II
EUROPEAN SOURCE
I
After going destroying a set of eared spinners every 1-2 years, I settled on the long beaker bar and a fitting for three-eared spinners from a source Tim recommended (thanks again Tim!!!). I then measured the extension to the breaker bar I needed to have the torque I wanted by pushng my hardest at its end and had the extesnion made at the local machine shop to order. I have not damaged a spinner since.

But even now, I do not regret the earlier crushed spinners.
New spinners are cheap compared to 4 new wheels and hubs. I have seen that
happen too
often with others.