1972 Shorland Series III brake problem

[917601]

I am new to the forum,and have many questions about my Shorland.I have not driven it regularly for 2 years.

First-Both my front brakes lock up solid and overheat when driving. After cooling off I can make it a few more blocks.Sounds like the shoes are dragging.What can cause BOTH wheels to lock up?
Ideas, first thing to look at?

Second-Can I use regular DOT 4 brake fluid (Prestone, etc) as no one carries Castrol LMA here(Atlanta).

Third-It has the 2.6, 6 cyl. engine(a dog).Plugs foul out quickly(black soot).What adjustments are made to the Zenith carb? I only know of the large adjustment screw on the bottom that raises the air piston.It also has an occaisional miss (every few seconds) at idle. Timing is set about 5-6 degrees, runs fine while driving.

All help appreciated.

[917601]

1972 Shorland, a Series III 109, 3/4 or 1 ton I am told.

[SafeAirOne]

I have a 2-for-1 answer for you. This happened to me before I ended up rebuilding the brake system in my 109:

There was no Castrol LMA locally available, so I used DOT4 fluid. Eventually, the Master cylinder began to leak internally, so I'd top it off every week or so. After a while, I noticed that my right front (off-side ) brake was having difficulty releasing. By the time I got to work (about 9 miles) I could fry an egg on my right front wheel hub.

It turns out that the DOT4 fluid deteriorated the rubber seals, and a small nugget of the deteriorated rubber worked its way into the right front wheel cylinder orifice and acted like a check-valve, letting brake pressure in, but not letting it out.

I thought it the DOT4 would be OK, but it wasn't--At least not the NAPA DOT4 I was using. My recommendation is to just order the Castrol, available from a number of Rover sources, including our hosts.

BTW--Nice Shorland! Regular Rovers attract plenty of attention dirving around town--I imagine YOUR town must be filled with people with snapped necks!

[JimCT]

Or you could just sell it to me and not worry about the hesitation.....Jim

[917601]

Follow up-
I was able to find the Castrol LM Dot 4 at the local Pep Boys-they even have Castrol Synthetic Brake fluid-???. I used the infamous bicycle tube bleed procedure and proceeded to bleed the brakes re-filling the main reservoir twice ( is that enough to purge the system?).No time to test drive-but I have regained full pedal travel and drove fwd/aft 20 times-seems to be fixed, no indication of dragging shoes.

On to my idle "popping" problem.I did read here one wizard thought it could be the carb adjusted too LEAN. I pulled the choke out 1/4 way and it idles great(exhaust smells rich tho). Next step, enrichen the idle with the large star screw on the bottom of the carb-(back out till air piston uplifted does not cause rise/drop in RPM-correct?)

After this 4 new 9x16 tires, shocks, bushings and hopefully "urban" ready.

Thank You. Pics upon completion.

[917601]

Bad news-took the Shorland for a drive, the front brakes did not seize up again but started dragging and went very hot.What is the logical cause? Master cylinder? wheel cylinders? Springs? Stumped.

[SafeAirOne]

Bad news-took the Shorland for a drive, the front brakes did not seize up again but started dragging and went very hot.What is the logical cause? Master cylinder? wheel cylinders? Springs? Stumped.

Yes, yes and yes. All logical causes. The springs connecting the front brake shoe to the back brake shoe on each wheel provide the force to retract the shoes when brake pedal is released. The brakes retract by pushing the wheel cylinder pistons together (dual-piston wheel cylinders) or back into the cylinder bore (single-piston cylinders like on 109 fronts) , sending brake fluid back through the lines and into the master cylinder and back into the reservoir.

Causes:

If the return springs are worn and broken, the shoes will not retract properly. Not likely in my opinion, but simple to check.

If the wheel cylinders/pistions are worn or pitted, the pistons will bind on the cylinder walls when it comes time to retract. This is a possibility--wheel cylinder bores are susceptible to pitting when brake fluid absorbs moisture, especially when the system is unused for long periods of time.

If the master cylinder/pistion is worn or pitted, the piston will bind on the cylinder walls when it comes time to retract. This is a less-likely possibility, however, master cylinder bores are susceptible to pitting when brake fluid absorbs moisture, especially when the system is unused for long periods of time. If, after applying and releasing the brakes, you immediately reapply the brakes and find that the pedal travels freely a ways before you feel the resistance of the master cylinder, the MC piston may be binding.

If there are tiny to medium black particles floating around or settled in the bottom of the master cylinder, your rubber parts are deteriorating and should be replaced. These particles could be causing a stoppage in certain parts of the brake plumbing. Forcing the fluid through one of these stoppages is easy when you're putting 1500 psi through the lines by stepping on the brake, but the fluid will not be able to return to the resivoir under the few psi provided by the brake return springs. Most susceptible are the choke-points in the plumbing such as the orifices in the master and wheel cylinders and any unions or tees in the lines.

Another item might be the rubber flex hoses--Sometimes these crumble on the inside but still look good on the outside. Results could be the same as in the above paragraph.

Finally, there may be some sort of mechanical restriction in the line, such as a kink or crush. Check for damaged lines.

So there--We've narrowed it down to every component in the brake system Except the fluid. Hope this helps!

[917601]

Safeairone-Thanks for a quick reply.Now it seems I have a full 8 hours work just troubleshooting-maybe more.Being a Shorland-I have to remove the front right tire to remove a large heavy "armored box" that surrounds the clutch and master cylinder.

My suspicion is the master cylinder as the rod going into the MC is out of travel (adjusted full length long and can not be extended further) and still has 1/4 inch "slop".

Best place to buy a new/rebuilt MC? The Shorland is a Series III 109, 1972, 1 ton(stated on title) but others have said it is a 3/4 ton(confusion).I can post pics later,and I plan to repair when wife and kids go on vacation in 3 weeks.

[917601]

I had some time and pulled the wheel cylinders fronts.All froze up solid-the piston on 2 cylinders immoveable even with a 1/2 drive breaker bar on the piston! Rebuilding not likely-looks like British Pacific has what is needed-but all parts places do not show any pictures! Can anyone confirm what I need? The Shorland has 2 cylinders on each fwd brake assy's.A casting number on the top left cylinder is-4674103035-.No reply from parts companies as it is a holiday weekend.Who has the best price for quality wheel cylinders?

[SafeAirOne]

Who has the best price for quality wheel cylinders?

There are numerous sources for the cylinders you need. Preices vary widely! There's not much to wheel cylinders, really. Just a lump of cast iron with a few ports drilled into it and a machined bore. Aluminum pistons are usually the most affected by moisture, turning into a powdery billet of corrosion. Stainless pistons are the way to go, if available.

Out of respect for our hosts, I'll not say anything good or bad about their current prices on whell cylinders...click on this thread to see an expample though (have an ambulance standing by):

http://www.roversnorth.com/forums/showthread.php?t=3858

There are other sources out there. I'll e-mail or PM them to you off-list if a few minutes. I SUSPECT that you will need 109 6-CYLINDER wheel cylinders (NOT the 4-cyl).

--Mark