OT: To the Caravan Owners - Brakes

Hi everyone.

@Moderators: If you find it too off-topic, please delete it without comment - but I know from the threads from early August that there are many caravan owners here.

I've just returned from my vacation for a few hours, and I have a question right away.

Not for the TDI, which ran perfectly, and reliably pulled the caravan back occasionally, but rather to the latter:

Even during the test drives before the vacation, I noticed that the brake drums (and the wheels) became quite warm, as if something was dragging. However, the wheels could be easily turned, and it even seemed to be less friction than with most car wheels. A strong push caused the wheel to rotate several times before it came to a stop.

Since the car had been sitting for a year, the logical explanation was a bit of rust on the fenders, which quickly deteriorated.

But it wasn't like that - while driving, the shop became warmer, and then, after I had fiddled with the brake lever of the trailer brake (which was very loose, so without any tension that could cause the brakes to slip), the wheels were cold when I checked them again, which confirmed my theory about surface rust.

During the next inspection (I wasn't entirely convinced about the safety), the rims were so hot after 100 km on the highway that water droplets on the wheel bolts immediately evaporated!

Due to the lack of tools, we went to a nearby auto repair shop, where one of the brakes had been completely disassembled - everything was fine, however, the wheel could hardly be turned in the raised state (presumably due to the expansion of the brake pads due to heat). After assembly, the wheel turned smoothly again, and the other one (which had now cooled down) also turned easily, so that it didn't need to be disassembled.

After 10 km of cautious driving, both were almost back to normal.

My thoughts (the mechanic also thought this was possible, but he suspected the cause was in the brake, such as worn return springs) were that the cables that connect the linkage to the wheel brakes were so heavy that the springs, after strong braking (the brake was set quite softly, so the lever initially pushes the lever together a bit, before anything happens - the brake then starts abruptly), didn't have enough force to completely pull the cable back, so the brake would drag. The rattling of the linkage also supports this, and that's why the wheels can be easily turned even when stationary or after rattling. It's illogical only that the vibrations during the ride are not sufficient.

Then, 100 km before the destination, I had freed the towing hitch, and disabled the braking system using the reverse lock and tape. (Note: Yes, this is illegal, but there was no other choice, and secondly, the permissible total weight of the trailer was only just above the permitted maximum weight for an unbraked trailer).

That worked perfectly, and the brakes remained ice-cold.

I would like to actually remove, lubricate, and possibly replace these Bowden cables that connect the master cylinder to the wheel brakes, but before that (it's quite a job), I need to clarify the following:

Does anyone know about this? Does anyone have better ideas?

For construction purposes:

The lever of the brake linkage acts on a rod that extends centrally under the chassis, from the center of the two mentioned Bowden cables. The handbrake also acts on this rod, but it cannot be used to create the effect. The Bowden cables both start parallel, so there is no cable that operates both brakes together; each has its own, starting from the point where the cable terminates.

You can adjust the length of the linkage on the front (this ensures that there is no slack, so the brakes don't slip when engaged), and the length of the Bowden cable at the rear - also to ensure that the brakes don't slip when engaged.

Best regards, and thank you very much,

Jan

I think that applying a little grease to all the relevant parts, especially those related to the lever mechanism, should help. The greasing should be done regularly, once a year. Often, these parts are either missing or, more commonly, covered in hardened grease.

Hello Jan,

It seems that the programmed route for your brakes is not correct. The brake should be adjusted so that its full effect occurs in the last third of the stroke of your towing mechanism.
It is also possible that the trailer damping device on the towing mechanism is faulty (this was the case with me). Then the trailer enters the trailer brake too often and too early, overloading the brakes thermally. For a free trailer, push the trailer attachment mechanism as far as possible and then wait to see if the damping device quickly and smoothly retracts the towing mechanism. If it does not, you should consider getting a new one (WARNING: Very expensive!). If the suspension produces a violent rebound when braking, then the shock absorber is definitely finished.

Hi everyone,

Quote:

It seems that the programmed route for your brakes is not correct. The brake should be adjusted so that its full effect occurs in the last third of the stroke of your towing mechanism.

This is correctly set up, or rather, it was (I set it up for the return trip so that the brake would not engage at all, in order to avoid the problem).

Quote:

It is also possible that the drawbar damper on the drawbar mechanism is malfunctioning (this was the case with me), which causes the trailer to enter the drawbar brake too often and too early, thereby overloading the brakes thermally. For free hanging, the loading system. As far as possible, press the brake firmly and then wait to see if the shock absorber quickly and smoothly retracts the braking mechanism. If it does not, you should consider getting a new one (WARNING: Very expensive!). If the trailer produces a strong rebound when braking, then the shock absorber is definitely finished.

Hmm... that also seems quite clear.

If I press the clutch in by hand (it's very difficult, but possible), and then release it, it remains exactly as I released it. Nothing comes out when it's pushed out. Last year, the pushrod was jammed. We then disassembled it, cleaned it, and also removed the damper, which doesn't contain anything that resembles a spring; it more closely resembles a (thin) shock absorber. In other words, if you push it together, it remains in that position. Must it be like this, or should there be a springy component in there that pushes them apart?

That's right, the rear-wheel drive setup makes the car quite lively, especially when it gets going (and the rear end does indeed get there in the final third of the run).

How about you - when you completely push in the clutch, and then release it - does it completely disassemble, or just the small piece until the brakes are loose? Do you have a spring on your damper, or does it look more like a shock absorber - perhaps the parts function like the gas pressure struts on trunk lids (that would also explain the behavior).

Best regards, and thank you very much.

Jan

Hello Jan,
That's right, the 'slush' effect is quite noticeable when it hits the brakes.
I experienced exactly the behavior you described when I improperly loaded my caravan. Due to excessive weight in the front, the loading brake became difficult to operate and only engaged late, but with considerable force. She also finds it difficult to cope with this.

I was able to lift the beam further if I stood on top of it. So, I thought I could probably support around 70kg. But apparently, standing on top of the beam creates enormous forces, at least a scale placed under the support wheel showed a reading against the 130kg maximum. After I had reloaded the campervan and only had 70kg inside, the braking was significantly better.

If not already done, please perform the 'person scale under the car support' test and be surprised...

PS: My suspension also doesn't retract, but remains in its position. However, this could also be due to the age of the camper (26 years). My father once told me that he was going to 'unplug' his (new) camper again.

Greetings
Private

Hi,

...it can't be the weight... the pendant was so heavy that it had a load of about 50 kilos (more than the car's coupling can handle). I didn't measure it with a scale, but it was still possible to pull it out from the front without having to strain too much (I weigh 60 kg, and I definitely won't be able to get much more out).

The pendant itself is 17 years old, but the lever mechanism was completely disassembled and lubricated last year, and it is still quite functional.

Best regards,

Jan

hi jan

So, for me it works like this: the entire mechanism can be folded in by hand, and when you release it, it returns to its original position completely. This is independent of the loading condition or anything else. The shock absorber is similar to a gas-pressure shock absorber. Check out www.pieper-gladbeck.de and search for 'shock absorber' or 'suspension strut'. You should find a lot of information there!

Okay, maybe it's also your suspension. You're the one who writes about it. It seems to be quite difficult. That could mean that the force the shock absorber applies isn't enough anymore! In my opinion, compressing it by hand should be easy and not just require extreme effort.

Hi Joergs,

thanks for the link! Exactly as in one of the pictures there, it looks like this. And... Bertil seems to have really nailed it with "sauteuer".

I'll take a look around a bit more, the page looks really interesting.

Best regards,

Jan

...

I'll take a look around a bit more, the page looks really interesting.



but be careful: the page is going to cost a fortune very quickly. Pieper is a representative of the faction!

I also weigh only 75kg and am more on the lean side than muscular (I was at the Bundeswehr, weighing 5kg and running 10km). Nevertheless, I was able to lift the trailer without overexerting myself, and I also thought I had lifted about 50kg (that's the maximum my Golf 3 can handle)... I really want to measure it.

However, I agree with joerg that the component should be able to be manually compressed.

However, with my old campervan, which I drive, it is normal that the parking brake does not automatically retract. I actually asked Hobby directly at the time (the factory is less than 10 km away, so I have several acquaintances working there).

I would, however, first make the brake easier to operate before considering a new shock absorber. The force of the shock absorber should also easily overcome the wind resistance, so the brake itself should be able to fully release without the shock absorber. Besides, the brake is stiff, just like yours.

However, with a 'disabled' brake, I would definitely advise against driving, even if the weight of the caravan is only slightly above the permitted maximum braked trailer weight. In an emergency, your braking distance will increase to deadly lengths with a momentum of approximately 1000 kg. I would prefer to start abruptly, as this will also ensure that the brakes function safely.

Hi Jan,

Jan6K wrote:

How about you - when you completely push in the clutch, and then release it - does it completely disassemble, or just the small piece until the brakes are loose? Do you have a spring on your damper, or does it look more like a shock absorber - perhaps the parts function like the gas pressure struts on trunk lids (that would also explain the behavior).

So, bei meinem alten Auflaufeinrichtung blieb sie auch immer hängen. Auch das Abschmieren hat nicht geholfen. Nach dem (unvermeidlichen) Unfall habe ich eine komplett neue Auflaufeinrichtung montiert, und diese kommt langsam und sauber heraus, aber mit etwas Kraft. Also, the "Auflaufschlag" is also gone.
The damper has a gas chamber that pushes it back out (similar to that of a gas-operated damper in a car or a trunk lid).

The entire camping setup cost around 350 euros (original ALKO).

Quote:

And... Bertil has really nailed it with "sauteuer".

... dabei ist der Pieper immer noch eine der günstigeren Sorten (zumindest in Deutschland) was die Dämpfer angeht. Wenn es ein ALKO Fahrgestell sein soll, kann ich dir die holländischen Nachbarn ans Herz legen. There, the ALKO items are up to 50% (!) cheaper (e.g., http://www.obelink.de).

... dabei ist der Pieper immer noch eine der günstigeren Sorten (zumindest in Deutschland) was die Dämpfer angeht. Wenn es ein ALKO Fahrgestell sein soll, kann ich dir die holländischen Nachbarn ans Herz legen. There, the ALKO items are up to 50% (!) cheaper (e.g., http://www.obelink.de).

You're right. In Germany, campers are really being asked to pay a high price. However, www.obelink.de only ships tents. If you want to buy from obelink, then you have to go to Holland and buy it there! Unfortunately! But obelink is quite cheap in terms of price!

Hi everyone,

after a few hours of tinkering, not much new, but still some things to eliminate:

Quote:

I also weigh only 75kg and am more on the lean side than muscular (I was at the Bundeswehr, weighing 5kg and running 10km). Nevertheless, I was able to lift the trailer without overexerting myself, and I also thought I had lifted about 50kg (that's the maximum my Golf 3 can handle)... I really want to measure it.

I can't stand with my legs wide apart and both hands raised, but rather standing to the side with one hand, so I can't lift more than 60 kg. I will, however, put a weight on it at some point in the near future.

Quote:

However, I agree with joerg that the piece should be manually compressed.

That definitely won't work, just by shaking and pushing forcefully. If the hook is attached to a braked car, it can be moved and pulled apart using pushing and pulling, and it can also be used to roll the car backward with just a slight slope of the ground.

Quote:

I would definitely start by making the brake easier to operate before considering a new shock. The force of the shock should also easily overcome the wind resistance, so the brake itself should be able to fully release without the shock. Besides, the brake is stiff, just like yours.

I thought the same about the wind – that's why it didn't bother me that it didn't come apart on its own.

We disassembled and inspected one of the brakes completely today. There's nothing heavy-duty about it; it doesn't drag or bind at all, and after every braking, it's immediately loose again with the handbrake.

After lubricating the Bowden cable (which, incidentally, was also quite easy), we then attempted to modify the lever mechanism. The lever, over which the rod is pushed forward, has two holes in which it can be attached; it was hanging in the upper one (resulting in a short path to the pivot point and therefore quite a strong force on the rod). We then attached it to the lower one, so that the force with which the brake is applied is reduced, and the path is correspondingly lengthened. The hope was to be able to control the jerks and, at the same time, not have to apply the brakes so intensely.

Resultat: The brakes still function (from full braking from 40 km/h to complete stopping of the trailer wheels), but there is almost no noticeable jerk anymore.

But: The brake rotors are still getting very hot

What was strange: The trailer could be easily pushed onto the yard after the ride, and rolled smoothly on a slight incline on its own. However, when I applied the handbrake firmly to make a small adjustment, it locked up. This must have meant that something in the system had become stuck and was freed again by rattling against the (relaxed) chassis. It might be the exact cause, but it couldn't be reproduced, especially since there's nothing in the brake that could get so stuck – and it would also have to affect both equally, since both get hot, and in one instance, both got stuck.

So, the "Bastelei" didn't really bring much today... next time, it's the "Schubstück" that will be in focus.

Interesting, perhaps also: When braking sharply from a slow pace, you can clearly see the object as it passes by, and then when the car comes to a standstill, it "flies away".

Quote:

However, with a "disabled" brake, I would definitely advise against driving, even if the weight of the caravan is only slightly above the permitted maximum braked trailer weight. In an emergency, your braking distance will increase to deadly lengths with a momentum of approximately 1000 kg. I would prefer to start abruptly, as this will also ensure that the brakes function safely.

No worries, I'm not suicidal. The Ibi weighs 1240 kg empty, plus 120 kg of crew, plus another 120 kg of luggage, so that's already 1480 kg, and the hanger weighs a maximum of 600 kg (it's a pretty small one). So, it wasn't that bad from a braking distance perspective - of course, it would have been more in an emergency braking situation.

By the way, a sharp start also doesn't work, I've tried that too. You can only achieve the effect by forcefully shaking the brake lever (gentle movements while driving are not sufficient).

To Bertil:

350 Euro... that's about what I expected for the whole thing. Regarding my recent experiences (especially the occasional issues with the handbrake), I'm not entirely convinced that it's solely the clutch or the damper.

ALKO is not the one, it's a French product (the "Dragoner 370" is the name of the box), and I believe the frame also comes from there.

What do you think about the option of attaching the brake lever – would you prefer to have the linkage move in a short (high force, longer path for the actuator) or long (lower force, shorter path for the actuator) manner?

What also surprises me about this brake hook is the evenness of both sides, which actually clearly points to the linkage or the suspension system. However, the linkage was loose. It could potentially get tangled in the back, but that seems very unlikely to me given the design (metal rod through a hole) - but I will check it again.

Best regards,

Jan

Hello everyone,

Even though it's not particularly impressive to me (it really should have happened sooner), here's the whole solution, maybe it will help someone else someday.

I had written that it had happened once before, by manually applying the handbrake, and that it hadn't happened again on that day.

Yesterday, we tried to provoke it, and eventually it worked - even though the handbrake was engaged, the brakes were still quite tight. A closer look at the pendant and careful examination of the mechanism has then revealed the solution:

At the front, there is the pivoting lever, through which the lever arm acts on the brake strut. Since we had lowered the latter further (see previous post, which creates a softer braking start due to less force on the brakes), the lower end of the handbrake catches the bolt with which the strut is attached, and tilts it slightly forward. This prevents it from being under tension because the handbrake pulls the strut much further, and this also does not interfere while driving because the handbrake is relaxed. When releasing again, the weight of the lever and the force of the return springs should push it back, but they didn't, because the lever is *very* heavy, and the brake therefore doesn't always fully release.

Previously, this wasn't noticeable because the handbrake lever doesn't move, and the movement of the pedal usually (but not always) pulls it back.

Further dissections then revealed a construction flaw:

This lever, the handbrake, and a distance sleeve are screwed onto a long bolt that passes through the trailer brake assembly, and is held in place with *one* nut. If you tighten them too much, the lever becomes difficult to operate. If you tighten them completely, the handbrake will also not move.

Originally, the mother was probably very loose (potentially dangerous!), but during the repair last year, it was probably tightened a bit more, which then made the lever heavier, so that the mechanism didn't always release properly.

A counter nut has now permanently solved the problem, and the test drive has confirmed that this was the solution.

However, thank you to everyone for their contributions, as the "Auflaufstossdaempfer" (presumably a specific component) will likely need to be replaced soon, and the "Scbubstueck" (another specific component) also needs to be replaced so that it functions more easily (as it has been hindering the operation of the lever).

Best regards,

Jan