[Tgo]

A few days ago the 6 year old Coido tyre inflator I had acted up in a strange way. I had to top up the air by 2-3 PSI in each tyre and it seemed to take a good 5 minutes per tyre. I decided to open it apart to have a look at its innards hoping to find something that I would be able to fix.

I thought of putting my observations down so that one gets to know how it works and if there are any serviceable parts in it. The first thing i learnt was that it was a simple piston type reciprocating pump where I was expecting it to have a diaphragm as the working element.

• The motor looks like a brushless (hoping very high) or a non serviceable brush type motor. It is the heaviest part in the whole pump. It is sandwiched between the two casing halves with two rubber isolator pads for damping.
• The bracket houses the main bearing which is a simple bronze bush. It had too much of a clearance for my liking. But on hindsight it might have been there for the crank to tilt slightly so that the con rod big end can be slid onto it.
  
  
  
• The crank was the only decently machined part with a hardened surface for longevity.
  
• The con-rod had no bearings on either ends.
  
• The piston was made from plastic and had a good quality rubber/silicone ring which had a groove to hold up some amount of lubricant.
  
• The cylinder bore was smooth but was out of round and this could be felt by touch.
  
• The cylinder head had the inlet and outlet valves in-built (press fitted/riveted).
  
  
  
• The inlet valve is just a thin sheet of metal allowing air into the cylinder (one direction only, at least in theory).
  
• The outlet valve seemed to be spring loaded and built into the outlet stem threaded onto the cylinder head. This had a soft rubber seat which seemed more functional than the sealing action provided by the thin sheet metal of the inlet valve pushing against the cylinder head to seal that port.
  
• Rest of the system looked like well built and leak proof plumbing which I did not want to disturb

The only servicable parts in this arrangement was the Piston Ring. Everything else had a consumable like built and quality of material. No bearings to grease, no damping pads that perished, no parts that seemed upgradable.

Before uploading this post, searched the internet to find: THIS

[Aditya]

Thread moved out from the Assembly Line. Thanks for sharing!

[SS-Traveller]

Originally Posted by Tgo

The cylinder bore was smooth but was out of round and this could be felt by touch.
...
The only servicable parts in this arrangement was the Piston Ring

Isn't there an inlet air filter of some kind that needs to be cleaned out occasionally?

[paragsachania]

Originally Posted by SS-Traveller

Isn't there an inlet air filter of some kind that needs to be cleaned out occasionally?

I don't recollect if there was any filter for the inlet.

I had dismantled this 5 years back when one of my friends asked me to repair it. Exactly then I realised how these "inflators" are designed and whatever casing/covering you see externally is merely a design to attract buyers and label with different models .

The construction of every inflator, right from the one that costs 900 bucks all the way to 5000/- is exactly the same. The only differentiating factor would be the quality of the motor that drives the pistons in the cylinders. I have noticed that even the Cylinder+Piston set-up is same for most of these inflators thus draining the claims of "Heavy-Duty" and et al that sellers advertise.

[SS-Traveller]

Originally Posted by paragsachania

I don't recollect if there was any filter for the inlet.

Okay. Because my tyre inflator has a felt-like washable air filter, which needs to be cleaned out occasionally. Goes a long way to protect the cylinder and piston from wearing out, I'm sure.

[vinodvayyat]

Originally Posted by paragsachania

The only differentiating factor would be the quality of the motor that drives the pistons in the cylinders. I have noticed that even the Cylinder+Piston set-up is same for most of these inflators thus draining the claims of "Heavy-Duty" and et al that sellers advertise.

Manufacturers might be using different bore/stroke numbers to make it heavy-duty. Needless to talk about RPM at which the motor runs (more RPM, the better). Other differentiating feature is number of cylinders. I use a twin cylinder for long which has faster air filling capability compared to single cylinder ones.

[paragsachania]

Originally Posted by vinodvayyat

Manufacturers might be using different bore/stroke numbers to make it heavy-duty. Needless to talk about RPM at which the motor runs (more RPM, the better). Other differentiating feature is number of cylinders. I use a twin cylinder for long which has faster air filling capability compared to single cylinder ones.

Twin Cylinders is something I have come across too and this is the case even with Heavy Duty foot pumps.

However, when it comes to size the cylinder most of them I have come across are one and the same. This is not something I am referring to on this thread. I have been telling about it on the inflator thread since quite a few years. Whether it is Coido, ResqTech, Windeck, Michelin or any other.

[Tgo]

Originally Posted by SS-Traveller

Isn't there an inlet air filter of some kind that needs to be cleaned out occasionally?

Do share a picture of your inflator. The filter seems like an illogical exclusion in my case.